138718640 has 40 divisors (see below), whose sum is σ = 341496000. Its totient is φ = 52222976.

The previous prime is 138718637. The next prime is 138718669. The reversal of 138718640 is 46817831.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×138718640² = 38485722166899200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 138718594 and 138718603.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 49640 + ... + 52359.

It is an arithmetic number, because the mean of its divisors is an integer number (8537400).

Almost surely, 2^138718640 is an apocalyptic number.

138718640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138718640 is an abundant number, since it is smaller than the sum of its proper divisors (202777360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

138718640 is a wasteful number, since it uses less digits than its factorization.

138718640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102029 (or 102023 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 38.

The square root of 138718640 is about 11777.8877562999. The cubic root of 138718640 is about 517.6603966544.

The spelling of 138718640 in words is "one hundred thirty-eight million, seven hundred eighteen thousand, six hundred forty".