21260404 has 48 divisors (see below), whose sum is σ = 44041536. Its totient is φ = 8870400.

The previous prime is 21260377. The next prime is 21260413. The reversal of 21260404 is 40406212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31834 + ... + 32494.

It is an arithmetic number, because the mean of its divisors is an integer number (917532).

Almost surely, 2^21260404 is an apocalyptic number.

It is an amenable number.

21260404 is an abundant number, since it is smaller than the sum of its proper divisors (22781132).

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

21260404 is a wasteful number, since it uses less digits than its factorization.

21260404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 736 (or 734 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 21260404 is about 4610.9005627968. The cubic root of 21260404 is about 277.0281090739.

Multiplying 21260404 by its sum of digits (19), we get a triangular number (403947676 = T₂₈₄₂₃).

Adding to 21260404 its reverse (40406212), we get a palindrome (61666616).

The spelling of 21260404 in words is "twenty-one million, two hundred sixty thousand, four hundred four".