21644243274 has 16 divisors (see below), whose sum is σ = 43295491008. Its totient is φ = 7213580352.

The previous prime is 21644243237. The next prime is 21644243329. The reversal of 21644243274 is 47234244612.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 251247 + ... + 326210.

It is an arithmetic number, because the mean of its divisors is an integer number (2705968188).

Almost surely, 2^21644243274 is an apocalyptic number.

21644243274 is an abundant number, since it is smaller than the sum of its proper divisors (21651247734).

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

21644243274 is a wasteful number, since it uses less digits than its factorization.

21644243274 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 583709.

The product of its digits is 258048, while the sum is 39.

Adding to 21644243274 its reverse (47234244612), we get a palindrome (68878487886).

The spelling of 21644243274 in words is "twenty-one billion, six hundred forty-four million, two hundred forty-three thousand, two hundred seventy-four".