138738656 has 36 divisors (see below), whose sum is σ = 312559128. Its totient is φ = 59383872.

The previous prime is 138738569. The next prime is 138738659. The reversal of 138738656 is 656837831.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 138738656.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138738659) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 175895 + ... + 176681.

It is an arithmetic number, because the mean of its divisors is an integer number (8682198).

Almost surely, 2^138738656 is an apocalyptic number.

138738656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

138738656 is an abundant number, since it is smaller than the sum of its proper divisors (173820472).

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

138738656 is an frugal number, since it uses more digits than its factorization.

138738656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1591 (or 796 counting only the distinct ones).

The product of its digits is 725760, while the sum is 47.

The square root of 138738656 is about 11778.7374535644. The cubic root of 138738656 is about 517.6852935540.

The spelling of 138738656 in words is "one hundred thirty-eight million, seven hundred thirty-eight thousand, six hundred fifty-six".