21619407645 has 24 divisors (see below), whose sum is σ = 40880335392. Its totient is φ = 10482136800.

The previous prime is 21619407619. The next prime is 21619407679. The reversal of 21619407645 is 54670491612.

21619407645 is a `hidden beast` number, since 21 + 619 + 4 + 0 + 7 + 6 + 4 + 5 = 666.

It is not a de Polignac number, because 21619407645 - 2⁵ = 21619407613 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 21619407645.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21837291 + ... + 21838280.

It is an arithmetic number, because the mean of its divisors is an integer number (1703347308).

Almost surely, 2^21619407645 is an apocalyptic number.

It is an amenable number.

21619407645 is a deficient number, since it is larger than the sum of its proper divisors (19260927747).

21619407645 is a wasteful number, since it uses less digits than its factorization.

21619407645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43675593 (or 43675590 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The spelling of 21619407645 in words is "twenty-one billion, six hundred nineteen million, four hundred seven thousand, six hundred forty-five".