21988831100625 has 105 divisors (see below), whose sum is σ = 41202950211181. Its totient is φ = 11725688466000.

The previous prime is 21988831100623. The next prime is 21988831100629. The reversal of 21988831100625 is 52600113888912.

The square root of 21988831100625 is 4689225.

It is a perfect power (a square), and thus also a powerful number.

21988831100625 is a `hidden beast` number, since 2 + 1 + 9 + 8 + 8 + 8 + 3 + 1 + 1 + 0 + 0 + 625 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1723924358289 + 20264906742336 = 1312983^2 + 4501656^2 .

It is not a de Polignac number, because 21988831100625 - 2¹ = 21988831100623 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21988831100623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 104 ways as a sum of consecutive naturals, for example, 3165223402 + ... + 3165230348.

Almost surely, 2^{21988831100625} is an apocalyptic number.

21988831100625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21988831100625 is the 4689225-th square number.

21988831100625 is the 2344613-rd centered octagonal number.

It is an amenable number.

21988831100625 is a deficient number, since it is larger than the sum of its proper divisors (19214119110556).

21988831100625 is an frugal number, since it uses more digits than its factorization.

21988831100625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13932 (or 6955 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 54.

The spelling of 21988831100625 in words is "twenty-one trillion, nine hundred eighty-eight billion, eight hundred thirty-one million, one hundred thousand, six hundred twenty-five".