21123531474 has 64 divisors (see below), whose sum is σ = 43895706624. Its totient is φ = 6772239936.

The previous prime is 21123531469. The next prime is 21123531493. The reversal of 21123531474 is 47413532112.

It is a super-2 number, since 2×21123531474² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4773627 + ... + 4778049.

It is an arithmetic number, because the mean of its divisors is an integer number (685870416).

Almost surely, 2^21123531474 is an apocalyptic number.

21123531474 is an abundant number, since it is smaller than the sum of its proper divisors (22772175150).

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

21123531474 is a wasteful number, since it uses less digits than its factorization.

21123531474 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4751.

The product of its digits is 20160, while the sum is 33.

The spelling of 21123531474 in words is "twenty-one billion, one hundred twenty-three million, five hundred thirty-one thousand, four hundred seventy-four".