138861841 has 4 divisors (see below), whose sum is σ = 140764132. Its totient is φ = 136959552.

The previous prime is 138861761. The next prime is 138861847. The reversal of 138861841 is 148168831.

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

It can be written as a sum of positive squares in 2 ways, for example, as 120121600 + 18740241 = 10960^2 + 4329^2 .

It is a cyclic number.

It is not a de Polignac number, because 138861841 - 2¹⁷ = 138730769 is a prime.

It is a super-2 number, since 2×138861841² = 38565221771818562, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 138861794 and 138861803.

It is not an unprimeable number, because it can be changed into a prime (138861847) 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, 951036 + ... + 951181.

It is an arithmetic number, because the mean of its divisors is an integer number (35191033).

Almost surely, 2^138861841 is an apocalyptic number.

It is an amenable number.

138861841 is a deficient number, since it is larger than the sum of its proper divisors (1902291).

138861841 is an equidigital number, since it uses as much as digits as its factorization.

138861841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1902290.

The product of its digits is 36864, while the sum is 40.

The square root of 138861841 is about 11783.9654191618. The cubic root of 138861841 is about 517.8384645113.

The spelling of 138861841 in words is "one hundred thirty-eight million, eight hundred sixty-one thousand, eight hundred forty-one".