138996540 has 48 divisors (see below), whose sum is σ = 432435360. Its totient is φ = 37065600.

The previous prime is 138996527. The next prime is 138996541. The reversal of 138996540 is 45699831.

It is a happy number.

138996540 is a `hidden beast` number, since 13 + 8 + 9 + 96 + 540 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138996541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 128161 + ... + 129240.

It is an arithmetic number, because the mean of its divisors is an integer number (9009070).

Almost surely, 2^138996540 is an apocalyptic number.

138996540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138996540 is an abundant number, since it is smaller than the sum of its proper divisors (293438820).

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

138996540 is a wasteful number, since it uses less digits than its factorization.

138996540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257419 (or 257411 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The square root of 138996540 is about 11789.6793849536. The cubic root of 138996540 is about 518.0058485846.

The spelling of 138996540 in words is "one hundred thirty-eight million, nine hundred ninety-six thousand, five hundred forty".