11520891987 has 16 divisors (see below), whose sum is σ = 17298232320. Its totient is φ = 6757120800.

The previous prime is 11520891979. The next prime is 11520891989. The reversal of 11520891987 is 78919802511.

It is not a de Polignac number, because 11520891987 - 2³ = 11520891979 is a prime.

It is a super-2 number, since 2×11520891987² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (11520891989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5629912 + ... + 5631957.

It is an arithmetic number, because the mean of its divisors is an integer number (1081139520).

Almost surely, 2^11520891987 is an apocalyptic number.

11520891987 is a deficient number, since it is larger than the sum of its proper divisors (5777340333).

11520891987 is a wasteful number, since it uses less digits than its factorization.

11520891987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11261914.

The product of its (nonzero) digits is 362880, while the sum is 51.

The spelling of 11520891987 in words is "eleven billion, five hundred twenty million, eight hundred ninety-one thousand, nine hundred eighty-seven".