21154557752 has 16 divisors (see below), whose sum is σ = 39668870400. Its totient is φ = 10576192320.

The previous prime is 21154557751. The next prime is 21154557791. The reversal of 21154557752 is 25775545112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21154557751) 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, 49877 + ... + 211652.

It is an arithmetic number, because the mean of its divisors is an integer number (2479304400).

Almost surely, 2^21154557752 is an apocalyptic number.

It is an amenable number.

21154557752 is a deficient number, since it is larger than the sum of its proper divisors (18514312648).

21154557752 is a wasteful number, since it uses less digits than its factorization.

21154557752 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271646 (or 271642 counting only the distinct ones).

The product of its digits is 490000, while the sum is 44.

The spelling of 21154557752 in words is "twenty-one billion, one hundred fifty-four million, five hundred fifty-seven thousand, seven hundred fifty-two".