138891661510 has 64 divisors (see below), whose sum is σ = 288123568128. Its totient is φ = 47219808384.

The previous prime is 138891661507. The next prime is 138891661523. The reversal of 138891661510 is 15166198831.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25218177 + ... + 25223683.

It is an arithmetic number, because the mean of its divisors is an integer number (4501930752).

Almost surely, 2^138891661510 is an apocalyptic number.

138891661510 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138891661510 is an abundant number, since it is smaller than the sum of its proper divisors (149231906618).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

138891661510 is a wasteful number, since it uses less digits than its factorization.

138891661510 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8485.

The product of its (nonzero) digits is 311040, while the sum is 49.

The spelling of 138891661510 in words is "one hundred thirty-eight billion, eight hundred ninety-one million, six hundred sixty-one thousand, five hundred ten".