21654732472 has 32 divisors (see below), whose sum is σ = 41412682080. Its totient is φ = 10613115520.

The previous prime is 21654732433. The next prime is 21654732479. The reversal of 21654732472 is 27423745612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21654732479) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 11923 + ... + 208450.

It is an arithmetic number, because the mean of its divisors is an integer number (1294146315).

Almost surely, 2^21654732472 is an apocalyptic number.

It is an amenable number.

21654732472 is a deficient number, since it is larger than the sum of its proper divisors (19757949608).

21654732472 is a wasteful number, since it uses less digits than its factorization.

21654732472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220623 (or 220619 counting only the distinct ones).

The product of its digits is 564480, while the sum is 43.

The spelling of 21654732472 in words is "twenty-one billion, six hundred fifty-four million, seven hundred thirty-two thousand, four hundred seventy-two".