138918210 has 16 divisors (see below), whose sum is σ = 333403776. Its totient is φ = 37044848.

The previous prime is 138918187. The next prime is 138918233. The reversal of 138918210 is 12819831.

It is an interprime number because it is at equal distance from previous prime (138918187) and next prime (138918233).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2315274 + ... + 2315333.

It is an arithmetic number, because the mean of its divisors is an integer number (20837736).

Almost surely, 2^138918210 is an apocalyptic number.

138918210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138918210 is an abundant number, since it is smaller than the sum of its proper divisors (194485566).

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

138918210 is a wasteful number, since it uses less digits than its factorization.

138918210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4630617.

The product of its (nonzero) digits is 3456, while the sum is 33.

The square root of 138918210 is about 11786.3569435174. The cubic root of 138918210 is about 517.9085247652.

It can be divided in two parts, 138918 and 210, that added together give a triangular number (139128 = T₅₂₇).

The spelling of 138918210 in words is "one hundred thirty-eight million, nine hundred eighteen thousand, two hundred ten".