21775657711 has 4 divisors (see below), whose sum is σ = 21776118624. Its totient is φ = 21775196800.

The previous prime is 21775657703. The next prime is 21775657733. The reversal of 21775657711 is 11775657712.

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

It is a cyclic number.

It is not a de Polignac number, because 21775657711 - 2³ = 21775657703 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21775657781) 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, 150295 + ... + 257176.

It is an arithmetic number, because the mean of its divisors is an integer number (5444029656).

Almost surely, 2^21775657711 is an apocalyptic number.

21775657711 is a deficient number, since it is larger than the sum of its proper divisors (460913).

21775657711 is an equidigital number, since it uses as much as digits as its factorization.

21775657711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 460912.

The product of its digits is 720300, while the sum is 49.

Subtracting from 21775657711 its reverse (11775657712), we obtain a palindrome (9999999999).

The spelling of 21775657711 in words is "twenty-one billion, seven hundred seventy-five million, six hundred fifty-seven thousand, seven hundred eleven".