139947688 has 8 divisors (see below), whose sum is σ = 262401930. Its totient is φ = 69973840.

The previous prime is 139947679. The next prime is 139947697. The reversal of 139947688 is 886749931.

139947688 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (139947679) and next prime (139947697).

It can be written as a sum of positive squares in only one way, i.e., 123609924 + 16337764 = 11118^2 + 4042^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8746723 + ... + 8746738.

Almost surely, 2^139947688 is an apocalyptic number.

It is an amenable number.

139947688 is a deficient number, since it is larger than the sum of its proper divisors (122454242).

139947688 is a wasteful number, since it uses less digits than its factorization.

139947688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17493467 (or 17493463 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 55.

The square root of 139947688 is about 11829.9487741917. The cubic root of 139947688 is about 519.1847283778.

The spelling of 139947688 in words is "one hundred thirty-nine million, nine hundred forty-seven thousand, six hundred eighty-eight".