21231004 has 12 divisors (see below), whose sum is σ = 37226728. Its totient is φ = 10594800.

The previous prime is 21230969. The next prime is 21231029. The reversal of 21231004 is 40013212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2742 + ... + 7069.

Almost surely, 2^21231004 is an apocalyptic number.

It is an amenable number.

21231004 is a deficient number, since it is larger than the sum of its proper divisors (15995724).

21231004 is a wasteful number, since it uses less digits than its factorization.

21231004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10356 (or 10354 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21231004 is about 4607.7113624879. The cubic root of 21231004 is about 276.9003538414.

Adding to 21231004 its reverse (40013212), we get a palindrome (61244216).

The spelling of 21231004 in words is "twenty-one million, two hundred thirty-one thousand, four".