138224628 has 18 divisors (see below), whose sum is σ = 349401234. Its totient is φ = 46074864.

The previous prime is 138224617. The next prime is 138224657. The reversal of 138224628 is 826422831.

138224628 is a `hidden beast` number, since 1 + 3 + 8 + 2 + 24 + 628 = 666.

138224628 is digitally balanced in base 2 and base 3, because in such bases 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., 129686544 + 8538084 = 11388^2 + 2922^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 3839573 = 138224628 / (1 + 3 + 8 + 2 + 2 + 4 + 6 + 2 + 8).

It is a junction number, because it is equal to n+sod(n) for n = 138224592 and 138224601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1919751 + ... + 1919822.

Almost surely, 2^138224628 is an apocalyptic number.

138224628 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

138224628 is an abundant number, since it is smaller than the sum of its proper divisors (211176606).

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

138224628 is a wasteful number, since it uses less digits than its factorization.

138224628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3839583 (or 3839578 counting only the distinct ones).

The product of its digits is 36864, while the sum is 36.

The square root of 138224628 is about 11756.8970396104. The cubic root of 138224628 is about 517.0451594053.

The spelling of 138224628 in words is "one hundred thirty-eight million, two hundred twenty-four thousand, six hundred twenty-eight".