21958913087 has 4 divisors (see below), whose sum is σ = 21978714840. Its totient is φ = 21939111336.

The previous prime is 21958913003. The next prime is 21958913113. The reversal of 21958913087 is 78031985912.

It is a happy number.

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 21958913087 - 2²⁴ = 21942135871 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 (21958913887) 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, 9899213 + ... + 9901430.

It is an arithmetic number, because the mean of its divisors is an integer number (5494678710).

Almost surely, 2^21958913087 is an apocalyptic number.

21958913087 is a deficient number, since it is larger than the sum of its proper divisors (19801753).

21958913087 is a wasteful number, since it uses less digits than its factorization.

21958913087 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19801752.

The product of its (nonzero) digits is 1088640, while the sum is 53.

The spelling of 21958913087 in words is "twenty-one billion, nine hundred fifty-eight million, nine hundred thirteen thousand, eighty-seven".