21451575132 has 72 divisors (see below), whose sum is σ = 58413491136. Its totient is φ = 6598502784.

The previous prime is 21451575113. The next prime is 21451575143. The reversal of 21451575132 is 23157515412.

21451575132 is a `hidden beast` number, since 2 + 1 + 4 + 51 + 575 + 1 + 32 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2638738 + ... + 2646854.

It is an arithmetic number, because the mean of its divisors is an integer number (811298488).

Almost surely, 2^21451575132 is an apocalyptic number.

It is an amenable number.

21451575132 is an abundant number, since it is smaller than the sum of its proper divisors (36961916004).

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

21451575132 is a wasteful number, since it uses less digits than its factorization.

21451575132 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13787 (or 13782 counting only the distinct ones).

The product of its digits is 42000, while the sum is 36.

The spelling of 21451575132 in words is "twenty-one billion, four hundred fifty-one million, five hundred seventy-five thousand, one hundred thirty-two".