3138728 has 32 divisors (see below), whose sum is σ = 6199200. Its totient is φ = 1487808.

The previous prime is 3138691. The next prime is 3138767. The reversal of 3138728 is 8278313.

It is a super-2 number, since 2×3138728² = 19703226915968, which contains 22 as substring.

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 3138694 and 3138703.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19175 + ... + 19337.

It is an arithmetic number, because the mean of its divisors is an integer number (193725).

Almost surely, 2^3138728 is an apocalyptic number.

It is an amenable number.

3138728 is a deficient number, since it is larger than the sum of its proper divisors (3060472).

3138728 is a wasteful number, since it uses less digits than its factorization.

3138728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281 (or 277 counting only the distinct ones).

The product of its digits is 8064, while the sum is 32.

The square root of 3138728 is about 1771.6455627467. The cubic root of 3138728 is about 146.4146590674.

The spelling of 3138728 in words is "three million, one hundred thirty-eight thousand, seven hundred twenty-eight".