138735720 has 128 divisors (see below), whose sum is σ = 486864000. Its totient is φ = 35043840.

The previous prime is 138735713. The next prime is 138735733. The reversal of 138735720 is 27537831.

138735720 is a `hidden beast` number, since 1 + 3 + 87 + 3 + 572 + 0 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17140 + ... + 23900.

It is an arithmetic number, because the mean of its divisors is an integer number (3803625).

Almost surely, 2^138735720 is an apocalyptic number.

138735720 is a gapful number since it is divisible by the number (10) 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 138735720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (243432000).

138735720 is an abundant number, since it is smaller than the sum of its proper divisors (348128280).

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

138735720 is a wasteful number, since it uses less digits than its factorization.

138735720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6800 (or 6790 counting only the distinct ones).

The product of its (nonzero) digits is 35280, while the sum is 36.

The square root of 138735720 is about 11778.6128215508. The cubic root of 138735720 is about 517.6816417606.

The spelling of 138735720 in words is "one hundred thirty-eight million, seven hundred thirty-five thousand, seven hundred twenty".