138765121 has 8 divisors (see below), whose sum is σ = 151530624. Its totient is φ = 126024720.

The previous prime is 138765119. The next prime is 138765139. The reversal of 138765121 is 121567831.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 138765121 - 2¹ = 138765119 is a prime.

It is a super-2 number, since 2×138765121² = 38511517612289282, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138765521) 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, 6415 + ... + 17851.

It is an arithmetic number, because the mean of its divisors is an integer number (18941328).

Almost surely, 2^138765121 is an apocalyptic number.

138765121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

138765121 is a deficient number, since it is larger than the sum of its proper divisors (12765503).

138765121 is a wasteful number, since it uses less digits than its factorization.

138765121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12551.

The product of its digits is 10080, while the sum is 34.

The square root of 138765121 is about 11779.8608226074. The cubic root of 138765121 is about 517.7182083658.

The spelling of 138765121 in words is "one hundred thirty-eight million, seven hundred sixty-five thousand, one hundred twenty-one".