139968591 has 32 divisors (see below), whose sum is σ = 218488320. Its totient is φ = 78052224.

The previous prime is 139968581. The next prime is 139968617. The reversal of 139968591 is 195869931.

It is a happy number.

It is not a de Polignac number, because 139968591 - 2¹⁴ = 139952207 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139968511) 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 31 ways as a sum of consecutive naturals, for example, 214021 + ... + 214673.

It is an arithmetic number, because the mean of its divisors is an integer number (6827760).

Almost surely, 2^139968591 is an apocalyptic number.

139968591 is a deficient number, since it is larger than the sum of its proper divisors (78519729).

139968591 is a wasteful number, since it uses less digits than its factorization.

139968591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 895.

The product of its digits is 524880, while the sum is 51.

The square root of 139968591 is about 11830.8322192481. The cubic root of 139968591 is about 519.2105760791.

The spelling of 139968591 in words is "one hundred thirty-nine million, nine hundred sixty-eight thousand, five hundred ninety-one".