138151881 has 12 divisors (see below), whose sum is σ = 228060352. Its totient is φ = 78943896.

The previous prime is 138151861. The next prime is 138151883. The reversal of 138151881 is 188151831.

It is a happy number.

138151881 is a `hidden beast` number, since 138 + 1 + 518 + 8 + 1 = 666.

It is not a de Polignac number, because 138151881 - 2⁶ = 138151817 is a prime.

It is a super-2 number, since 2×138151881² = 38171884447676322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138151883) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1096381 + ... + 1096506.

Almost surely, 2^138151881 is an apocalyptic number.

It is an amenable number.

138151881 is a deficient number, since it is larger than the sum of its proper divisors (89908471).

138151881 is a wasteful number, since it uses less digits than its factorization.

138151881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2192900 (or 2192897 counting only the distinct ones).

The product of its digits is 7680, while the sum is 36.

The square root of 138151881 is about 11753.8028314244. The cubic root of 138151881 is about 516.9544373073.

The spelling of 138151881 in words is "one hundred thirty-eight million, one hundred fifty-one thousand, eight hundred eighty-one".