21581199274 has 32 divisors (see below), whose sum is σ = 33451938576. Its totient is φ = 10435399680.

The previous prime is 21581199193. The next prime is 21581199293. The reversal of 21581199274 is 47299118512.

It can be written as a sum of positive squares in 8 ways, for example, as 4095104049 + 17486095225 = 63993^2 + 132235^2 .

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 15 ways as a sum of consecutive naturals, for example, 13895682 + ... + 13897234.

Almost surely, 2^21581199274 is an apocalyptic number.

21581199274 is a deficient number, since it is larger than the sum of its proper divisors (11870739302).

21581199274 is a wasteful number, since it uses less digits than its factorization.

21581199274 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2970.

The product of its digits is 362880, while the sum is 49.

The spelling of 21581199274 in words is "twenty-one billion, five hundred eighty-one million, one hundred ninety-nine thousand, two hundred seventy-four".