139639749 has 4 divisors (see below), whose sum is σ = 186186336. Its totient is φ = 93093164.

The previous prime is 139639723. The next prime is 139639757. The reversal of 139639749 is 947936931.

139639749 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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.

It is a cyclic number.

It is not a de Polignac number, because 139639749 - 2⁹ = 139639237 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139639769) 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, 23273289 + ... + 23273294.

It is an arithmetic number, because the mean of its divisors is an integer number (46546584).

Almost surely, 2^139639749 is an apocalyptic number.

It is an amenable number.

139639749 is a deficient number, since it is larger than the sum of its proper divisors (46546587).

139639749 is an equidigital number, since it uses as much as digits as its factorization.

139639749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46546586.

The product of its digits is 1102248, while the sum is 51.

The square root of 139639749 is about 11816.9263770238. The cubic root of 139639749 is about 518.8036463802.

The spelling of 139639749 in words is "one hundred thirty-nine million, six hundred thirty-nine thousand, seven hundred forty-nine".