11451981 has 8 divisors (see below), whose sum is σ = 15682144. Its totient is φ = 7428240.

The previous prime is 11451977. The next prime is 11452027. The reversal of 11451981 is 18915411.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 11451981 - 2² = 11451977 is a prime.

It is a super-2 number, since 2×11451981² = 262295737648722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11451901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51475 + ... + 51696.

It is an arithmetic number, because the mean of its divisors is an integer number (1960268).

Almost surely, 2^11451981 is an apocalyptic number.

It is an amenable number.

11451981 is a deficient number, since it is larger than the sum of its proper divisors (4230163).

11451981 is a wasteful number, since it uses less digits than its factorization.

11451981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103211.

The product of its digits is 1440, while the sum is 30.

The square root of 11451981 is about 3384.0775700329. The cubic root of 11451981 is about 225.4032669174.

The spelling of 11451981 in words is "eleven million, four hundred fifty-one thousand, nine hundred eighty-one".