138540628 has 12 divisors (see below), whose sum is σ = 255206560. Its totient is φ = 65624472.

The previous prime is 138540601. The next prime is 138540629. The reversal of 138540628 is 826045831.

It is a happy number.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138540629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 911376 + ... + 911527.

Almost surely, 2^138540628 is an apocalyptic number.

It is an amenable number.

138540628 is a deficient number, since it is larger than the sum of its proper divisors (116665932).

138540628 is a wasteful number, since it uses less digits than its factorization.

138540628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1822926 (or 1822924 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 37.

The square root of 138540628 is about 11770.3282876902. The cubic root of 138540628 is about 517.4388710108.

The spelling of 138540628 in words is "one hundred thirty-eight million, five hundred forty thousand, six hundred twenty-eight".