21102712 has 16 divisors (see below), whose sum is σ = 41895360. Its totient is φ = 9930624.

The previous prime is 21102709. The next prime is 21102737. The reversal of 21102712 is 21720112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77448 + ... + 77719.

It is an arithmetic number, because the mean of its divisors is an integer number (2618460).

Almost surely, 2^21102712 is an apocalyptic number.

It is an amenable number.

21102712 is a deficient number, since it is larger than the sum of its proper divisors (20792648).

21102712 is a wasteful number, since it uses less digits than its factorization.

21102712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155190 (or 155186 counting only the distinct ones).

The product of its (nonzero) digits is 56, while the sum is 16.

The square root of 21102712 is about 4593.7688230907. The cubic root of 21102712 is about 276.3414872757.

Adding to 21102712 its reverse (21720112), we get a palindrome (42822824).

The spelling of 21102712 in words is "twenty-one million, one hundred two thousand, seven hundred twelve".