139591809 has 16 divisors (see below), whose sum is σ = 236346240. Its totient is φ = 79766640.

The previous prime is 139591801. The next prime is 139591813. The reversal of 139591809 is 908195931.

It is not a de Polignac number, because 139591809 - 2³ = 139591801 is a prime.

It is not an unprimeable number, because it can be changed into a prime (139591801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 369102 + ... + 369479.

It is an arithmetic number, because the mean of its divisors is an integer number (14771640).

Almost surely, 2^139591809 is an apocalyptic number.

It is an amenable number.

139591809 is a deficient number, since it is larger than the sum of its proper divisors (96754431).

139591809 is an equidigital number, since it uses as much as digits as its factorization.

139591809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 738597 (or 738591 counting only the distinct ones).

The product of its (nonzero) digits is 87480, while the sum is 45.

The square root of 139591809 is about 11814.8977566461. The cubic root of 139591809 is about 518.7442690807.

The spelling of 139591809 in words is "one hundred thirty-nine million, five hundred ninety-one thousand, eight hundred nine".