138720951 has 16 divisors (see below), whose sum is σ = 208330720. Its totient is φ = 91212480.

The previous prime is 138720943. The next prime is 138720973. The reversal of 138720951 is 159027831.

138720951 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 138720951 - 2³ = 138720943 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 (138720991) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33220 + ... + 37161.

It is an arithmetic number, because the mean of its divisors is an integer number (13020670).

Almost surely, 2^138720951 is an apocalyptic number.

138720951 is a deficient number, since it is larger than the sum of its proper divisors (69609769).

138720951 is an equidigital number, since it uses as much as digits as its factorization.

138720951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70463 (or 70457 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 36.

The square root of 138720951 is about 11777.9858634658. The cubic root of 138720951 is about 517.6632713138.

The spelling of 138720951 in words is "one hundred thirty-eight million, seven hundred twenty thousand, nine hundred fifty-one".