21642561333 has 24 divisors (see below), whose sum is σ = 31964395008. Its totient is φ = 14107537152.

The previous prime is 21642561299. The next prime is 21642561337. The reversal of 21642561333 is 33316524612.

21642561333 is a `hidden beast` number, since 2 + 1 + 6 + 4 + 2 + 5 + 613 + 33 = 666.

It is not a de Polignac number, because 21642561333 - 2²² = 21638367029 is a prime.

It is a super-2 number, since 2×21642561333² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21642561337) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 76885 + ... + 221802.

It is an arithmetic number, because the mean of its divisors is an integer number (1331849792).

Almost surely, 2^21642561333 is an apocalyptic number.

It is an amenable number.

21642561333 is a deficient number, since it is larger than the sum of its proper divisors (10321833675).

21642561333 is a wasteful number, since it uses less digits than its factorization.

21642561333 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298873 (or 298870 counting only the distinct ones).

The product of its digits is 77760, while the sum is 36.

The spelling of 21642561333 in words is "twenty-one billion, six hundred forty-two million, five hundred sixty-one thousand, three hundred thirty-three".