139191988 has 24 divisors (see below), whose sum is σ = 277755912. Its totient is φ = 60463104.

The previous prime is 139191977. The next prime is 139191991. The reversal of 139191988 is 889191931.

It is a happy number.

139191988 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 1411344 + 137780644 = 1188^2 + 11738^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77845 + ... + 79612.

It is an arithmetic number, because the mean of its divisors is an integer number (11573163).

Almost surely, 2^139191988 is an apocalyptic number.

It is an amenable number.

139191988 is a deficient number, since it is larger than the sum of its proper divisors (138563924).

139191988 is a wasteful number, since it uses less digits than its factorization.

139191988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157491 (or 157489 counting only the distinct ones).

The product of its digits is 139968, while the sum is 49.

The square root of 139191988 is about 11797.9654178168. The cubic root of 139191988 is about 518.2485303814.

The spelling of 139191988 in words is "one hundred thirty-nine million, one hundred ninety-one thousand, nine hundred eighty-eight".