21887087657 has 4 divisors (see below), whose sum is σ = 21895670016. Its totient is φ = 21878505300.

The previous prime is 21887087627. The next prime is 21887087681. The reversal of 21887087657 is 75678078812.

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 21887087657 - 2¹⁴ = 21887071273 is a prime.

It is a super-2 number, since 2×21887087657² (a number of 21 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 = 21887087596 and 21887087605.

It is not an unprimeable number, because it can be changed into a prime (21887087627) 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, 4287353 + ... + 4292454.

It is an arithmetic number, because the mean of its divisors is an integer number (5473917504).

Almost surely, 2^21887087657 is an apocalyptic number.

It is an amenable number.

21887087657 is a deficient number, since it is larger than the sum of its proper divisors (8582359).

21887087657 is an equidigital number, since it uses as much as digits as its factorization.

21887087657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8582358.

The product of its (nonzero) digits is 10536960, while the sum is 59.

The spelling of 21887087657 in words is "twenty-one billion, eight hundred eighty-seven million, eighty-seven thousand, six hundred fifty-seven".