138717261 has 24 divisors (see below), whose sum is σ = 203355360. Its totient is φ = 91110816.

The previous prime is 138717259. The next prime is 138717283. The reversal of 138717261 is 162717831.

138717261 is a `hidden beast` number, since 1 + 387 + 17 + 261 = 666.

It is not a de Polignac number, because 138717261 - 2¹ = 138717259 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138717211) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 272275 + ... + 272783.

It is an arithmetic number, because the mean of its divisors is an integer number (8473140).

Almost surely, 2^138717261 is an apocalyptic number.

It is an amenable number.

138717261 is a deficient number, since it is larger than the sum of its proper divisors (64638099).

138717261 is a wasteful number, since it uses less digits than its factorization.

138717261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 905 (or 902 counting only the distinct ones).

The product of its digits is 14112, while the sum is 36.

The square root of 138717261 is about 11777.8292142483. The cubic root of 138717261 is about 517.6586812972.

The spelling of 138717261 in words is "one hundred thirty-eight million, seven hundred seventeen thousand, two hundred sixty-one".