21252236454 has 48 divisors (see below), whose sum is σ = 46899609120. Its totient is φ = 6953708160.

The previous prime is 21252236443. The next prime is 21252236521. The reversal of 21252236454 is 45463225212.

21252236454 is a `hidden beast` number, since 2 + 1 + 2 + 5 + 2 + 2 + 3 + 645 + 4 = 666.

It is a Curzon number.

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, 256354 + ... + 328970.

It is an arithmetic number, because the mean of its divisors is an integer number (977075190).

Almost surely, 2^21252236454 is an apocalyptic number.

21252236454 is an abundant number, since it is smaller than the sum of its proper divisors (25647372666).

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

21252236454 is a wasteful number, since it uses less digits than its factorization.

21252236454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72925 (or 72922 counting only the distinct ones).

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

The spelling of 21252236454 in words is "twenty-one billion, two hundred fifty-two million, two hundred thirty-six thousand, four hundred fifty-four".