138280028 has 6 divisors (see below), whose sum is σ = 241990056. Its totient is φ = 69140012.

The previous prime is 138279983. The next prime is 138280039. The reversal of 138280028 is 820082831.

It is a super-2 number, since 2×138280028² = 38242732287361568, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 138279976 and 138280003.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 17285000 + ... + 17285007.

It is an arithmetic number, because the mean of its divisors is an integer number (40331676).

Almost surely, 2^138280028 is an apocalyptic number.

It is an amenable number.

138280028 is a deficient number, since it is larger than the sum of its proper divisors (103710028).

138280028 is a wasteful number, since it uses less digits than its factorization.

138280028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34570011 (or 34570009 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 32.

The square root of 138280028 is about 11759.2528674232. The cubic root of 138280028 is about 517.1142268748.

The spelling of 138280028 in words is "one hundred thirty-eight million, two hundred eighty thousand, twenty-eight".