31028939 has 4 divisors (see below), whose sum is σ = 31041720. Its totient is φ = 31016160.

The previous prime is 31028897. The next prime is 31028947. The reversal of 31028939 is 93982013.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 93982013 = 1091 ⋅86143.

It is a cyclic number.

It is not a de Polignac number, because 31028939 - 2¹² = 31024843 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31028899 and 31028908.

It is not an unprimeable number, because it can be changed into a prime (31028989) 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, 1502 + ... + 8019.

It is an arithmetic number, because the mean of its divisors is an integer number (7760430).

Almost surely, 2^31028939 is an apocalyptic number.

31028939 is a deficient number, since it is larger than the sum of its proper divisors (12781).

31028939 is an equidigital number, since it uses as much as digits as its factorization.

31028939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12780.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 31028939 is about 5570.3625555254. The cubic root of 31028939 is about 314.2357858211.

The spelling of 31028939 in words is "thirty-one million, twenty-eight thousand, nine hundred thirty-nine".