138720751 has 8 divisors (see below), whose sum is σ = 155887200. Its totient is φ = 122482272.

The previous prime is 138720689. The next prime is 138720787. The reversal of 138720751 is 157027831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138720751 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138720551) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 231676 + ... + 232273.

It is an arithmetic number, because the mean of its divisors is an integer number (19485900).

Almost surely, 2^138720751 is an apocalyptic number.

138720751 is a deficient number, since it is larger than the sum of its proper divisors (17166449).

138720751 is a wasteful number, since it uses less digits than its factorization.

138720751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 463985.

The product of its (nonzero) digits is 11760, while the sum is 34.

The square root of 138720751 is about 11777.9773730467. The cubic root of 138720751 is about 517.6630225345.

The spelling of 138720751 in words is "one hundred thirty-eight million, seven hundred twenty thousand, seven hundred fifty-one".