12921720 has 64 divisors (see below), whose sum is σ = 44305920. Its totient is φ = 2953344.

The previous prime is 12921679. The next prime is 12921763. The reversal of 12921720 is 2712921.

12921720 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6852 + ... + 8531.

It is an arithmetic number, because the mean of its divisors is an integer number (692280).

Almost surely, 2^12921720 is an apocalyptic number.

12921720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12921720 is an abundant number, since it is smaller than the sum of its proper divisors (31384200).

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

12921720 is a wasteful number, since it uses less digits than its factorization.

12921720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15404 (or 15400 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 24.

The square root of 12921720 is about 3594.6794015600. The cubic root of 12921720 is about 234.6605632165.

The spelling of 12921720 in words is "twelve million, nine hundred twenty-one thousand, seven hundred twenty".