139964639 has 4 divisors (see below), whose sum is σ = 140314080. Its totient is φ = 139615200.

The previous prime is 139964623. The next prime is 139964641. The reversal of 139964639 is 936469931.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 139964639 - 2⁴ = 139964623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139964339) 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, 174119 + ... + 174920.

It is an arithmetic number, because the mean of its divisors is an integer number (35078520).

Almost surely, 2^139964639 is an apocalyptic number.

139964639 is a deficient number, since it is larger than the sum of its proper divisors (349441).

139964639 is an equidigital number, since it uses as much as digits as its factorization.

139964639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 349440.

The product of its digits is 944784, while the sum is 50.

The square root of 139964639 is about 11830.6651968518. The cubic root of 139964639 is about 519.2056894125.

The spelling of 139964639 in words is "one hundred thirty-nine million, nine hundred sixty-four thousand, six hundred thirty-nine".