21302404 has 12 divisors (see below), whose sum is σ = 37552284. Its totient is φ = 10573184.

The previous prime is 21302399. The next prime is 21302419. The reversal of 21302404 is 40420312.

It can be written as a sum of positive squares in 2 ways, for example, as 18232900 + 3069504 = 4270^2 + 1752^2 .

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, 18889 + ... + 19984.

It is an arithmetic number, because the mean of its divisors is an integer number (3129357).

Almost surely, 2^21302404 is an apocalyptic number.

It is an amenable number.

21302404 is a deficient number, since it is larger than the sum of its proper divisors (16249880).

21302404 is a wasteful number, since it uses less digits than its factorization.

21302404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39014 (or 39012 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 21302404 is about 4615.4527405229. The cubic root of 21302404 is about 277.2104124017.

Adding to 21302404 its reverse (40420312), we get a palindrome (61722716).

The spelling of 21302404 in words is "twenty-one million, three hundred two thousand, four hundred four".