12990381 has 4 divisors (see below), whose sum is σ = 17320512. Its totient is φ = 8660252.

The previous prime is 12990371. The next prime is 12990403. The reversal of 12990381 is 18309921.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12990381 - 2⁷ = 12990253 is a prime.

It is a super-2 number, since 2×12990381² = 337499997050322, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12990311) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2165061 + ... + 2165066.

It is an arithmetic number, because the mean of its divisors is an integer number (4330128).

Almost surely, 2^12990381 is an apocalyptic number.

It is an amenable number.

12990381 is a deficient number, since it is larger than the sum of its proper divisors (4330131).

12990381 is an equidigital number, since it uses as much as digits as its factorization.

12990381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4330130.

The product of its (nonzero) digits is 3888, while the sum is 33.

The square root of 12990381 is about 3604.2171133271. The cubic root of 12990381 is about 235.0754609027.

The spelling of 12990381 in words is "twelve million, nine hundred ninety thousand, three hundred eighty-one".