138891540 has 24 divisors (see below), whose sum is σ = 388896480. Its totient is φ = 37037728.

The previous prime is 138891521. The next prime is 138891569. The reversal of 138891540 is 45198831.

It is a congruent number.

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, 1157370 + ... + 1157489.

It is an arithmetic number, because the mean of its divisors is an integer number (16204020).

Almost surely, 2^138891540 is an apocalyptic number.

138891540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138891540 is an abundant number, since it is smaller than the sum of its proper divisors (250004940).

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

138891540 is a wasteful number, since it uses less digits than its factorization.

138891540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2314871 (or 2314869 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 39.

The square root of 138891540 is about 11785.2254963577. The cubic root of 138891540 is about 517.8753793521.

The spelling of 138891540 in words is "one hundred thirty-eight million, eight hundred ninety-one thousand, five hundred forty".