138186440 has 32 divisors (see below), whose sum is σ = 355337280. Its totient is φ = 47378112.

The previous prime is 138186431. The next prime is 138186463. The reversal of 138186440 is 44681831.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 138186440.

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, 246482 + ... + 247041.

It is an arithmetic number, because the mean of its divisors is an integer number (11104290).

Almost surely, 2^138186440 is an apocalyptic number.

138186440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138186440 is an abundant number, since it is smaller than the sum of its proper divisors (217150840).

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

138186440 is a wasteful number, since it uses less digits than its factorization.

138186440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 493541 (or 493537 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 138186440 is about 11755.2728594448. The cubic root of 138186440 is about 516.9975394805.

The spelling of 138186440 in words is "one hundred thirty-eight million, one hundred eighty-six thousand, four hundred forty".