138355992 has 64 divisors (see below), whose sum is σ = 385353600. Its totient is φ = 45995040.

The previous prime is 138355981. The next prime is 138356011. The reversal of 138355992 is 299553831.

138355992 is a `hidden beast` number, since 1 + 3 + 8 + 3 + 559 + 92 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 117567 + ... + 118737.

It is an arithmetic number, because the mean of its divisors is an integer number (6021150).

Almost surely, 2^138355992 is an apocalyptic number.

138355992 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138355992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (192676800).

138355992 is an abundant number, since it is smaller than the sum of its proper divisors (246997608).

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

138355992 is a wasteful number, since it uses less digits than its factorization.

138355992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1733 (or 1723 counting only the distinct ones).

The product of its digits is 291600, while the sum is 45.

The square root of 138355992 is about 11762.4823910601. The cubic root of 138355992 is about 517.2089016077.

It can be divided in two parts, 1383 and 55992, that added together give a palindrome (57375).

The spelling of 138355992 in words is "one hundred thirty-eight million, three hundred fifty-five thousand, nine hundred ninety-two".