11319981 has 4 divisors (see below), whose sum is σ = 15093312. Its totient is φ = 7546652.

The previous prime is 11319967. The next prime is 11319983. The reversal of 11319981 is 18991311.

It is a happy number.

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 11319981 - 2⁵ = 11319949 is a prime.

It is a super-2 number, since 2×11319981² = 256283939680722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11319983) 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, 1886661 + ... + 1886666.

It is an arithmetic number, because the mean of its divisors is an integer number (3773328).

Almost surely, 2^11319981 is an apocalyptic number.

It is an amenable number.

11319981 is a deficient number, since it is larger than the sum of its proper divisors (3773331).

11319981 is an equidigital number, since it uses as much as digits as its factorization.

11319981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3773330.

The product of its digits is 1944, while the sum is 33.

The square root of 11319981 is about 3364.5179446690. The cubic root of 11319981 is about 224.5338893918.

The spelling of 11319981 in words is "eleven million, three hundred nineteen thousand, nine hundred eighty-one".