20465157657021 has 32 divisors (see below), whose sum is σ = 34033402291200. Its totient is φ = 10627063246080.

The previous prime is 20465157657019. The next prime is 20465157657029. The reversal of 20465157657021 is 12075675156402.

It is not a de Polignac number, because 20465157657021 - 2¹ = 20465157657019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20465157657029) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16860076 + ... + 18033093.

It is an arithmetic number, because the mean of its divisors is an integer number (1063543821600).

Almost surely, 2^{20465157657021} is an apocalyptic number.

20465157657021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20465157657021 is a deficient number, since it is larger than the sum of its proper divisors (13568244634179).

20465157657021 is a wasteful number, since it uses less digits than its factorization.

20465157657021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34895729.

The product of its (nonzero) digits is 3528000, while the sum is 51.

The spelling of 20465157657021 in words is "twenty trillion, four hundred sixty-five billion, one hundred fifty-seven million, six hundred fifty-seven thousand, twenty-one".