138891626 has 4 divisors (see below), whose sum is σ = 208337442. Its totient is φ = 69445812.

The previous prime is 138891607. The next prime is 138891629. The reversal of 138891626 is 626198831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 626198831 = 1217 ⋅514543.

It can be written as a sum of positive squares in only one way, i.e., 131079601 + 7812025 = 11449^2 + 2795^2 .

It is not an unprimeable number, because it can be changed into a prime (138891629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34722905 + ... + 34722908.

Almost surely, 2^138891626 is an apocalyptic number.

138891626 is a deficient number, since it is larger than the sum of its proper divisors (69445816).

138891626 is an equidigital number, since it uses as much as digits as its factorization.

138891626 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69445815.

The product of its digits is 124416, while the sum is 44.

The square root of 138891626 is about 11785.2291449933. The cubic root of 138891626 is about 517.8754862395.

The spelling of 138891626 in words is "one hundred thirty-eight million, eight hundred ninety-one thousand, six hundred twenty-six".