138253988 has 24 divisors (see below), whose sum is σ = 244647480. Its totient is φ = 68359680.

The previous prime is 138253909. The next prime is 138254023. The reversal of 138253988 is 889352831.

It can be written as a sum of positive squares in 4 ways, for example, as 71537764 + 66716224 = 8458^2 + 8168^2 .

It is a super-2 number, since 2×138253988² = 38228330395808288, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 166358 + ... + 167186.

It is an arithmetic number, because the mean of its divisors is an integer number (10193645).

Almost surely, 2^138253988 is an apocalyptic number.

It is an amenable number.

138253988 is a deficient number, since it is larger than the sum of its proper divisors (106393492).

138253988 is a wasteful number, since it uses less digits than its factorization.

138253988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1247 (or 1245 counting only the distinct ones).

The product of its digits is 414720, while the sum is 47.

The square root of 138253988 is about 11758.1456020922. The cubic root of 138253988 is about 517.0817649688.

The spelling of 138253988 in words is "one hundred thirty-eight million, two hundred fifty-three thousand, nine hundred eighty-eight".