138871990 has 32 divisors (see below), whose sum is σ = 256796064. Its totient is φ = 54051840.

The previous prime is 138871987. The next prime is 138871991. The reversal of 138871990 is 99178831.

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 138871990.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138871991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57997 + ... + 60343.

It is an arithmetic number, because the mean of its divisors is an integer number (8024877).

Almost surely, 2^138871990 is an apocalyptic number.

138871990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138871990 is a deficient number, since it is larger than the sum of its proper divisors (117924074).

138871990 is a wasteful number, since it uses less digits than its factorization.

138871990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2512.

The product of its (nonzero) digits is 108864, while the sum is 46.

The square root of 138871990 is about 11784.3960388303. The cubic root of 138871990 is about 517.8510799630.

The spelling of 138871990 in words is "one hundred thirty-eight million, eight hundred seventy-one thousand, nine hundred ninety".