21615625444051 has 4 divisors (see below), whose sum is σ = 21633623468104. Its totient is φ = 21597627420000.

The previous prime is 21615625444033. The next prime is 21615625444057. The reversal of 21615625444051 is 15044452651612.

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 21615625444051 - 2¹¹ = 21615625442003 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21615625443992 and 21615625444010.

It is not an unprimeable number, because it can be changed into a prime (21615625444057) 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, 8999010225 + ... + 8999012626.

It is an arithmetic number, because the mean of its divisors is an integer number (5408405867026).

Almost surely, 2^{21615625444051} is an apocalyptic number.

21615625444051 is a deficient number, since it is larger than the sum of its proper divisors (17998024053).

21615625444051 is a wasteful number, since it uses less digits than its factorization.

21615625444051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17998024052.

The product of its (nonzero) digits is 1152000, while the sum is 46.

The spelling of 21615625444051 in words is "twenty-one trillion, six hundred fifteen billion, six hundred twenty-five million, four hundred forty-four thousand, fifty-one".