21704418397925 has 6 divisors (see below), whose sum is σ = 26913478813458. Its totient is φ = 17363534718320.

The previous prime is 21704418397919. The next prime is 21704418397979. The reversal of 21704418397925 is 52979381440712.

It can be written as a sum of positive squares in 3 ways, for example, as 323097885889 + 21381320512036 = 568417^2 + 4623994^2 .

It is not a de Polignac number, because 21704418397925 - 2³⁶ = 21635698921189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 434088367934 + ... + 434088367983.

It is an arithmetic number, because the mean of its divisors is an integer number (4485579802243).

Almost surely, 2^{21704418397925} is an apocalyptic number.

21704418397925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21704418397925 is a deficient number, since it is larger than the sum of its proper divisors (5209060415533).

21704418397925 is an equidigital number, since it uses as much as digits as its factorization.

21704418397925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 868176735927 (or 868176735922 counting only the distinct ones).

The product of its (nonzero) digits is 30481920, while the sum is 62.

The spelling of 21704418397925 in words is "twenty-one trillion, seven hundred four billion, four hundred eighteen million, three hundred ninety-seven thousand, nine hundred twenty-five".