138193664 has 72 divisors (see below), whose sum is σ = 320237568. Its totient is φ = 58291200.

The previous prime is 138193651. The next prime is 138193667. The reversal of 138193664 is 466391831.

It is not an unprimeable number, because it can be changed into a prime (138193667) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119489 + ... + 120639.

It is an arithmetic number, because the mean of its divisors is an integer number (4447744).

Almost surely, 2^138193664 is an apocalyptic number.

138193664 is a gapful number since it is divisible by the number (14) 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 138193664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160118784).

138193664 is an abundant number, since it is smaller than the sum of its proper divisors (182043904).

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

138193664 is an equidigital number, since it uses as much as digits as its factorization.

138193664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1241 (or 1227 counting only the distinct ones).

The product of its digits is 93312, while the sum is 41.

The square root of 138193664 is about 11755.5801217975. The cubic root of 138193664 is about 517.0065483846.

The spelling of 138193664 in words is "one hundred thirty-eight million, one hundred ninety-three thousand, six hundred sixty-four".