21323404 has 24 divisors (see below), whose sum is σ = 38185056. Its totient is φ = 10416000.

The previous prime is 21323371. The next prime is 21323417. The reversal of 21323404 is 40432312.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68409 + ... + 68719.

It is an arithmetic number, because the mean of its divisors is an integer number (1591044).

Almost surely, 2^21323404 is an apocalyptic number.

It is an amenable number.

21323404 is a deficient number, since it is larger than the sum of its proper divisors (16861652).

21323404 is a wasteful number, since it uses less digits than its factorization.

21323404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 657 (or 655 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 21323404 is about 4617.7271465516. The cubic root of 21323404 is about 277.3014742177.

Adding to 21323404 its reverse (40432312), we get a palindrome (61755716).

The spelling of 21323404 in words is "twenty-one million, three hundred twenty-three thousand, four hundred four".