21504131492 has 12 divisors (see below), whose sum is σ = 38550089676. Its totient is φ = 10489820160.

The previous prime is 21504131489. The next prime is 21504131507. The reversal of 21504131492 is 29413140512.

It can be written as a sum of positive squares in 2 ways, for example, as 12639155776 + 8864975716 = 112424^2 + 94154^2 .

It is a super-2 number, since 2×21504131492² (a number of 21 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65561213 + ... + 65561540.

It is an arithmetic number, because the mean of its divisors is an integer number (3212507473).

Almost surely, 2^21504131492 is an apocalyptic number.

It is an amenable number.

21504131492 is a deficient number, since it is larger than the sum of its proper divisors (17045958184).

21504131492 is a wasteful number, since it uses less digits than its factorization.

21504131492 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131122798 (or 131122796 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The spelling of 21504131492 in words is "twenty-one billion, five hundred four million, one hundred thirty-one thousand, four hundred ninety-two".