21398441012657 has 4 divisors (see below), whose sum is σ = 21399630559860. Its totient is φ = 21397251465456.

The previous prime is 21398441012623. The next prime is 21398441012677. The reversal of 21398441012657 is 75621014489312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16852658829601 + 4545782183056 = 4105199^2 + 2132084^2 .

It is a cyclic number.

It is not a de Polignac number, because 21398441012657 - 2³² = 21394146045361 is a prime.

It is a super-2 number, since 2×21398441012657² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21398441012599 and 21398441012608.

It is not an unprimeable number, because it can be changed into a prime (21398441012677) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 594746618 + ... + 594782595.

It is an arithmetic number, because the mean of its divisors is an integer number (5349907639965).

It is a 2-persistent number, because it is pandigital, and so is 2⋅21398441012657 = 42796882025314, but 3⋅21398441012657 = 64195323037971 is not.

Almost surely, 2^{21398441012657} is an apocalyptic number.

It is an amenable number.

21398441012657 is a deficient number, since it is larger than the sum of its proper divisors (1189547203).

21398441012657 is a wasteful number, since it uses less digits than its factorization.

21398441012657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1189547202.

The product of its (nonzero) digits is 2903040, while the sum is 53.

The spelling of 21398441012657 in words is "twenty-one trillion, three hundred ninety-eight billion, four hundred forty-one million, twelve thousand, six hundred fifty-seven".