11981477387 has 32 divisors (see below), whose sum is σ = 14132363520. Its totient is φ = 10040526720.

The previous prime is 11981477363. The next prime is 11981477393. The reversal of 11981477387 is 78377418911.

It is a cyclic number.

It is not a de Polignac number, because 11981477387 - 2¹² = 11981473291 is a prime.

It is not an unprimeable number, because it can be changed into a prime (11981477317) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2486993 + ... + 2491805.

It is an arithmetic number, because the mean of its divisors is an integer number (441636360).

Almost surely, 2^11981477387 is an apocalyptic number.

11981477387 is a deficient number, since it is larger than the sum of its proper divisors (2150886133).

11981477387 is a wasteful number, since it uses less digits than its factorization.

11981477387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5163.

The product of its digits is 2370816, while the sum is 56.

The spelling of 11981477387 in words is "eleven billion, nine hundred eighty-one million, four hundred seventy-seven thousand, three hundred eighty-seven".