21803109725 has 12 divisors (see below), whose sum is σ = 27037906740. Its totient is φ = 17441164800.

The previous prime is 21803109707. The next prime is 21803109743. The reversal of 21803109725 is 52790130812.

It is an interprime number because it is at equal distance from previous prime (21803109707) and next prime (21803109743).

It can be written as a sum of positive squares in 6 ways, for example, as 1644221401 + 20158888324 = 40549^2 + 141982^2 .

It is not a de Polignac number, because 21803109725 - 2²⁸ = 21534674269 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 430541 + ... + 478509.

It is an arithmetic number, because the mean of its divisors is an integer number (2253158895).

Almost surely, 2^21803109725 is an apocalyptic number.

21803109725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21803109725 is a deficient number, since it is larger than the sum of its proper divisors (5234797015).

21803109725 is a wasteful number, since it uses less digits than its factorization.

21803109725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66160 (or 66155 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 38.

The spelling of 21803109725 in words is "twenty-one billion, eight hundred three million, one hundred nine thousand, seven hundred twenty-five".