21400304 has 20 divisors (see below), whose sum is σ = 43266576. Its totient is φ = 10234752.

The previous prime is 21400277. The next prime is 21400343. The reversal of 21400304 is 40300412.

It is a super-2 number, since 2×21400304² = 915946022584832, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28709 + ... + 29444.

Almost surely, 2^21400304 is an apocalyptic number.

It is an amenable number.

21400304 is an abundant number, since it is smaller than the sum of its proper divisors (21866272).

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

21400304 is a wasteful number, since it uses less digits than its factorization.

21400304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58184 (or 58178 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 21400304 is about 4626.0462600367. The cubic root of 21400304 is about 277.6344244973.

Adding to 21400304 its reverse (40300412), we get a palindrome (61700716).

The spelling of 21400304 in words is "twenty-one million, four hundred thousand, three hundred four".