21120507 has 10 divisors (see below), whose sum is σ = 31550508. Its totient is φ = 14080284.

The previous prime is 21120503. The next prime is 21120523. The reversal of 21120507 is 70502112.

It is not a de Polignac number, because 21120507 - 2² = 21120503 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21120507.

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 (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 130293 + ... + 130454.

Almost surely, 2^21120507 is an apocalyptic number.

21120507 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21120507 is a deficient number, since it is larger than the sum of its proper divisors (10430001).

21120507 is an equidigital number, since it uses as much as digits as its factorization.

21120507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260759 (or 260750 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 18.

The square root of 21120507 is about 4595.7052777566. The cubic root of 21120507 is about 276.4191410417.

Adding to 21120507 its reverse (70502112), we get a palindrome (91622619).

The spelling of 21120507 in words is "twenty-one million, one hundred twenty thousand, five hundred seven".