138904784 has 10 divisors (see below), whose sum is σ = 269128050. Its totient is φ = 69452384.

The previous prime is 138904783. The next prime is 138904789. The reversal of 138904784 is 487409831.

It can be written as a sum of positive squares in only one way, i.e., 122323600 + 16581184 = 11060^2 + 4072^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138904783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4340759 + ... + 4340790.

It is an arithmetic number, because the mean of its divisors is an integer number (26912805).

Almost surely, 2^138904784 is an apocalyptic number.

It is an amenable number.

138904784 is a deficient number, since it is larger than the sum of its proper divisors (130223266).

138904784 is an equidigital number, since it uses as much as digits as its factorization.

138904784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8681557 (or 8681551 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 44.

The square root of 138904784 is about 11785.7873729336. The cubic root of 138904784 is about 517.8918394944.

The spelling of 138904784 in words is "one hundred thirty-eight million, nine hundred four thousand, seven hundred eighty-four".