12921540 has 24 divisors (see below), whose sum is σ = 36180480. Its totient is φ = 3445728.

The previous prime is 12921527. The next prime is 12921583. The reversal of 12921540 is 4512921.

It is a self number, because there is not a number n which added to its sum of digits gives 12921540.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 107620 + ... + 107739.

It is an arithmetic number, because the mean of its divisors is an integer number (1507520).

Almost surely, 2^12921540 is an apocalyptic number.

12921540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12921540 is an abundant number, since it is smaller than the sum of its proper divisors (23258940).

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

12921540 is a wasteful number, since it uses less digits than its factorization.

12921540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215371 (or 215369 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 12921540 is about 3594.6543644696. The cubic root of 12921540 is about 234.6594736015.

The spelling of 12921540 in words is "twelve million, nine hundred twenty-one thousand, five hundred forty".