11391864381 has 10 divisors (see below), whose sum is σ = 17017476542. Its totient is φ = 7594576200.

The previous prime is 11391864359. The next prime is 11391864383. The reversal of 11391864381 is 18346819311.

11391864381 is a `hidden beast` number, since 1 + 1 + 39 + 186 + 438 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 5776760025 + 5615104356 = 76005^2 + 74934^2 .

It is not a de Polignac number, because 11391864381 - 2⁵ = 11391864349 is a prime.

It is a super-2 number, since 2×11391864381² (a number of 21 digits) 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 (11391864383) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 70320070 + ... + 70320231.

Almost surely, 2^11391864381 is an apocalyptic number.

It is an amenable number.

11391864381 is a deficient number, since it is larger than the sum of its proper divisors (5625612161).

11391864381 is an equidigital number, since it uses as much as digits as its factorization.

11391864381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140640313 (or 140640304 counting only the distinct ones).

The product of its digits is 124416, while the sum is 45.

The spelling of 11391864381 in words is "eleven billion, three hundred ninety-one million, eight hundred sixty-four thousand, three hundred eighty-one".