21544642574 has 16 divisors (see below), whose sum is σ = 39774725088. Its totient is φ = 8523155232.

The previous prime is 21544642513. The next prime is 21544642577. The reversal of 21544642574 is 47524644512.

It is a happy number.

21544642574 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21544642577) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59188397 + ... + 59188760.

It is an arithmetic number, because the mean of its divisors is an integer number (2485920318).

Almost surely, 2^21544642574 is an apocalyptic number.

21544642574 is a deficient number, since it is larger than the sum of its proper divisors (18230082514).

21544642574 is a wasteful number, since it uses less digits than its factorization.

21544642574 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118377179.

The product of its digits is 1075200, while the sum is 44.

The spelling of 21544642574 in words is "twenty-one billion, five hundred forty-four million, six hundred forty-two thousand, five hundred seventy-four".