1139987521 has 4 divisors (see below), whose sum is σ = 1176761344. Its totient is φ = 1103213700.

The previous prime is 1139987507. The next prime is 1139987531. The reversal of 1139987521 is 1257899311.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1257899311 = 41 ⋅30680471.

It is a cyclic number.

It is not a de Polignac number, because 1139987521 - 2⁵ = 1139987489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1139987531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18386865 + ... + 18386926.

It is an arithmetic number, because the mean of its divisors is an integer number (294190336).

Almost surely, 2^1139987521 is an apocalyptic number.

It is an amenable number.

1139987521 is a deficient number, since it is larger than the sum of its proper divisors (36773823).

1139987521 is an equidigital number, since it uses as much as digits as its factorization.

1139987521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36773822.

The product of its digits is 136080, while the sum is 46.

The square root of 1139987521 is about 33763.7012337214. The cubic root of 1139987521 is about 1044.6401150799.

The spelling of 1139987521 in words is "one billion, one hundred thirty-nine million, nine hundred eighty-seven thousand, five hundred twenty-one".