138609432 has 192 divisors, whose sum is σ = 443439360. Its totient is φ = 38707200.

The previous prime is 138609413. The next prime is 138609461. The reversal of 138609432 is 234906831.

138609432 is a `hidden beast` number, since 1 + 3 + 8 + 609 + 43 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 493132 + ... + 493412.

It is an arithmetic number, because the mean of its divisors is an integer number (2309580).

Almost surely, 2^138609432 is an apocalyptic number.

138609432 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 138609432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (221719680).

138609432 is an abundant number, since it is smaller than the sum of its proper divisors (304829928).

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

138609432 is a wasteful number, since it uses less digits than its factorization.

138609432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 354 (or 347 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 138609432 is about 11773.2506980867. The cubic root of 138609432 is about 517.5245160968.

The spelling of 138609432 in words is "one hundred thirty-eight million, six hundred nine thousand, four hundred thirty-two".