21619087765 has 32 divisors (see below), whose sum is σ = 30999490560. Its totient is φ = 14287795200.

The previous prime is 21619087757. The next prime is 21619087849. The reversal of 21619087765 is 56778091612.

It is not a de Polignac number, because 21619087765 - 2³ = 21619087757 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 371541 + ... + 425770.

It is an arithmetic number, because the mean of its divisors is an integer number (968734080).

Almost surely, 2^21619087765 is an apocalyptic number.

It is an amenable number.

21619087765 is a deficient number, since it is larger than the sum of its proper divisors (9380402795).

21619087765 is a wasteful number, since it uses less digits than its factorization.

21619087765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 797373.

The product of its (nonzero) digits is 1270080, while the sum is 52.

The spelling of 21619087765 in words is "twenty-one billion, six hundred nineteen million, eighty-seven thousand, seven hundred sixty-five".