2107819921 has 9 divisors (see below), whose sum is σ = 2179479099. Its totient is φ = 2038448400.

The previous prime is 2107819877. The next prime is 2107819949. The reversal of 2107819921 is 1299187012.

The square root of 2107819921 is 45911.

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

It can be written as a sum of positive squares in only one way, i.e., 902341521 + 1205478400 = 30039^2 + 34720^2 .

It is not a de Polignac number, because 2107819921 - 2⁷ = 2107819793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2107819121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1422501 + ... + 1423981.

Almost surely, 2^2107819921 is an apocalyptic number.

2107819921 is the 45911-st square number.

2107819921 is the 22956-th centered octagonal number.

It is an amenable number.

2107819921 is a deficient number, since it is larger than the sum of its proper divisors (71659178).

2107819921 is an frugal number, since it uses more digits than its factorization.

2107819921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3024 (or 1512 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 40.

The cubic root of 2107819921 is about 1282.1667242844.

The spelling of 2107819921 in words is "two billion, one hundred seven million, eight hundred nineteen thousand, nine hundred twenty-one".