20772477257 has 4 divisors (see below), whose sum is σ = 23739974016. Its totient is φ = 17804980500.

The previous prime is 20772477233. The next prime is 20772477307. The reversal of 20772477257 is 75277427702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20772477257 - 2⁸ = 20772477001 is a prime.

It is a super-2 number, since 2×20772477257² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20772474257) 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, 1483748369 + ... + 1483748382.

It is an arithmetic number, because the mean of its divisors is an integer number (5934993504).

Almost surely, 2^20772477257 is an apocalyptic number.

It is an amenable number.

20772477257 is a deficient number, since it is larger than the sum of its proper divisors (2967496759).

20772477257 is an equidigital number, since it uses as much as digits as its factorization.

20772477257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2967496758.

The product of its (nonzero) digits is 2689120, while the sum is 50.

The spelling of 20772477257 in words is "twenty billion, seven hundred seventy-two million, four hundred seventy-seven thousand, two hundred fifty-seven".