12921390 has 32 divisors (see below), whose sum is σ = 34457760. Its totient is φ = 3445632.

The previous prime is 12921373. The next prime is 12921397. The reversal of 12921390 is 9312921.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12921397) 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 15 ways as a sum of consecutive naturals, for example, 23659 + ... + 24198.

It is an arithmetic number, because the mean of its divisors is an integer number (1076805).

Almost surely, 2^12921390 is an apocalyptic number.

12921390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

12921390 is an abundant number, since it is smaller than the sum of its proper divisors (21536370).

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

12921390 is a wasteful number, since it uses less digits than its factorization.

12921390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47873 (or 47867 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 12921390 is about 3594.6335000943. The cubic root of 12921390 is about 234.6585655814.

The spelling of 12921390 in words is "twelve million, nine hundred twenty-one thousand, three hundred ninety".