21120504 has 16 divisors (see below), whose sum is σ = 52801320. Its totient is φ = 7040160.

The previous prime is 21120503. The next prime is 21120523. The reversal of 21120504 is 40502112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120503) by changing a digit.

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, 439987 + ... + 440034.

Almost surely, 2^21120504 is an apocalyptic number.

21120504 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21120504 is an abundant number, since it is smaller than the sum of its proper divisors (31680816).

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

21120504 is a wasteful number, since it uses less digits than its factorization.

21120504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 880030 (or 880026 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 21120504 is about 4595.7049513649. The cubic root of 21120504 is about 276.4191279540.

Adding to 21120504 its reverse (40502112), we get a palindrome (61622616).

The spelling of 21120504 in words is "twenty-one million, one hundred twenty thousand, five hundred four".