12891990 has 16 divisors (see below), whose sum is σ = 30940848. Its totient is φ = 3437856.

The previous prime is 12891973. The next prime is 12892027. The reversal of 12891990 is 9919821.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 214837 + ... + 214896.

It is an arithmetic number, because the mean of its divisors is an integer number (1933803).

Almost surely, 2^12891990 is an apocalyptic number.

12891990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

12891990 is an abundant number, since it is smaller than the sum of its proper divisors (18048858).

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

12891990 is a wasteful number, since it uses less digits than its factorization.

12891990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 429743.

The product of its (nonzero) digits is 11664, while the sum is 39.

The square root of 12891990 is about 3590.5417418546. The cubic root of 12891990 is about 234.4804577863.

The spelling of 12891990 in words is "twelve million, eight hundred ninety-one thousand, nine hundred ninety".