21642315555 has 32 divisors (see below), whose sum is σ = 40539760128. Its totient is φ = 9652320000.

The previous prime is 21642315533. The next prime is 21642315557. The reversal of 21642315555 is 55551324612.

It is not a de Polignac number, because 21642315555 - 2¹² = 21642311459 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21642315557) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2509321 + ... + 2517930.

It is an arithmetic number, because the mean of its divisors is an integer number (1266867504).

Almost surely, 2^21642315555 is an apocalyptic number.

21642315555 is a deficient number, since it is larger than the sum of its proper divisors (18897444573).

21642315555 is a wasteful number, since it uses less digits than its factorization.

21642315555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5027307.

The product of its digits is 180000, while the sum is 39.

The spelling of 21642315555 in words is "twenty-one billion, six hundred forty-two million, three hundred fifteen thousand, five hundred fifty-five".