20957270897 has 4 divisors (see below), whose sum is σ = 22190051556. Its totient is φ = 19724490240.

The previous prime is 20957270809. The next prime is 20957270903. The reversal of 20957270897 is 79807275902.

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 9991201936 + 10966068961 = 99956^2 + 104719^2 .

It is a cyclic number.

It is not a de Polignac number, because 20957270897 - 2¹⁸ = 20957008753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20957270497) 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, 616390304 + ... + 616390337.

It is an arithmetic number, because the mean of its divisors is an integer number (5547512889).

Almost surely, 2^20957270897 is an apocalyptic number.

It is an amenable number.

20957270897 is a deficient number, since it is larger than the sum of its proper divisors (1232780659).

20957270897 is a wasteful number, since it uses less digits than its factorization.

20957270897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1232780658.

The product of its (nonzero) digits is 4445280, while the sum is 56.

The spelling of 20957270897 in words is "twenty billion, nine hundred fifty-seven million, two hundred seventy thousand, eight hundred ninety-seven".