21012451404 has 48 divisors (see below), whose sum is σ = 57547623168. Its totient is φ = 5841298368.

The previous prime is 21012451399. The next prime is 21012451433. The reversal of 21012451404 is 40415421012.

It is a super-2 number, since 2×21012451404² (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 (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3377274 + ... + 3383489.

It is an arithmetic number, because the mean of its divisors is an integer number (1198908816).

Almost surely, 2^21012451404 is an apocalyptic number.

It is an amenable number.

21012451404 is an abundant number, since it is smaller than the sum of its proper divisors (36535171764).

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

21012451404 is a wasteful number, since it uses less digits than its factorization.

21012451404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6760814 (or 6760812 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

Adding to 21012451404 its reverse (40415421012), we get a palindrome (61427872416).

The spelling of 21012451404 in words is "twenty-one billion, twelve million, four hundred fifty-one thousand, four hundred four".