21552236424 has 24 divisors (see below), whose sum is σ = 58370640510. Its totient is φ = 7184078784.

The previous prime is 21552236399. The next prime is 21552236429. The reversal of 21552236424 is 42463225512.

21552236424 is a `hidden beast` number, since 2 + 1 + 5 + 5 + 2 + 2 + 3 + 642 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 21175488324 + 376748100 = 145518^2 + 19410^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21552236429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 149668237 + ... + 149668380.

Almost surely, 2^21552236424 is an apocalyptic number.

21552236424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21552236424 is an abundant number, since it is smaller than the sum of its proper divisors (36818404086).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21552236424 is a wasteful number, since it uses less digits than its factorization.

21552236424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299336629 (or 299336622 counting only the distinct ones).

The product of its digits is 115200, while the sum is 36.

The spelling of 21552236424 in words is "twenty-one billion, five hundred fifty-two million, two hundred thirty-six thousand, four hundred twenty-four".