21395476795257 has 8 divisors (see below), whose sum is σ = 31697002659680. Its totient is φ = 14263651196820.

The previous prime is 21395476795219. The next prime is 21395476795337. The reversal of 21395476795257 is 75259767459312.

21395476795257 is a `hidden beast` number, since 2 + 1 + 3 + 9 + 547 + 6 + 79 + 5 + 2 + 5 + 7 = 666.

It is not a de Polignac number, because 21395476795257 - 2⁶ = 21395476795193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21395476795657) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 396212533219 + ... + 396212533272.

It is an arithmetic number, because the mean of its divisors is an integer number (3962125332460).

Almost surely, 2^{21395476795257} is an apocalyptic number.

21395476795257 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

21395476795257 is a deficient number, since it is larger than the sum of its proper divisors (10301525864423).

21395476795257 is an equidigital number, since it uses as much as digits as its factorization.

21395476795257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 792425066500 (or 792425066494 counting only the distinct ones).

The product of its digits is 1000188000, while the sum is 72.

The spelling of 21395476795257 in words is "twenty-one trillion, three hundred ninety-five billion, four hundred seventy-six million, seven hundred ninety-five thousand, two hundred fifty-seven".