138890831 has 4 divisors (see below), whose sum is σ = 143680200. Its totient is φ = 134101464.

The previous prime is 138890827. The next prime is 138890849. The reversal of 138890831 is 138098831.

It is a happy number.

138890831 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 138890831 - 2² = 138890827 is a prime.

It is a super-2 number, since 2×138890831² = 38581325871741122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138890891) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2394641 + ... + 2394698.

It is an arithmetic number, because the mean of its divisors is an integer number (35920050).

Almost surely, 2^138890831 is an apocalyptic number.

138890831 is a deficient number, since it is larger than the sum of its proper divisors (4789369).

138890831 is an equidigital number, since it uses as much as digits as its factorization.

138890831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4789368.

The product of its (nonzero) digits is 41472, while the sum is 41.

The square root of 138890831 is about 11785.1954162839. The cubic root of 138890831 is about 517.8744981507.

The spelling of 138890831 in words is "one hundred thirty-eight million, eight hundred ninety thousand, eight hundred thirty-one".