138790628 has 6 divisors (see below), whose sum is σ = 242883606. Its totient is φ = 69395312.

The previous prime is 138790621. The next prime is 138790643. The reversal of 138790628 is 826097831.

138790628 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 82119844 + 56670784 = 9062^2 + 7528^2 .

It is not an unprimeable number, because it can be changed into a prime (138790621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 17348825 + ... + 17348832.

It is an arithmetic number, because the mean of its divisors is an integer number (40480601).

Almost surely, 2^138790628 is an apocalyptic number.

It is an amenable number.

138790628 is a deficient number, since it is larger than the sum of its proper divisors (104092978).

138790628 is a wasteful number, since it uses less digits than its factorization.

138790628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34697661 (or 34697659 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 44.

The square root of 138790628 is about 11780.9434257194. The cubic root of 138790628 is about 517.7499277422.

The spelling of 138790628 in words is "one hundred thirty-eight million, seven hundred ninety thousand, six hundred twenty-eight".