11181265921 has 8 divisors (see below), whose sum is σ = 12794352704. Its totient is φ = 9572119920.

The previous prime is 11181265919. The next prime is 11181265957. The reversal of 11181265921 is 12956218111.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 11181265921 - 2¹ = 11181265919 is a prime.

It is a super-2 number, since 2×11181265921² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (11181265621) by changing a digit.

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, 979110 + ... + 990463.

It is an arithmetic number, because the mean of its divisors is an integer number (1599294088).

Almost surely, 2^11181265921 is an apocalyptic number.

It is an amenable number.

11181265921 is a deficient number, since it is larger than the sum of its proper divisors (1613086783).

11181265921 is an equidigital number, since it uses as much as digits as its factorization.

11181265921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1970391.

The product of its digits is 8640, while the sum is 37.

The spelling of 11181265921 in words is "eleven billion, one hundred eighty-one million, two hundred sixty-five thousand, nine hundred twenty-one".