31028139 has 24 divisors (see below), whose sum is σ = 46060560. Its totient is φ = 20120832.

The previous prime is 31028093. The next prime is 31028143. The reversal of 31028139 is 93182013.

31028139 = T₂ + T₃ + ... + T₅₇₀.

It is not a de Polignac number, because 31028139 - 2¹² = 31024043 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31028149) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 54247 + ... + 54815.

It is an arithmetic number, because the mean of its divisors is an integer number (1919190).

Almost surely, 2^31028139 is an apocalyptic number.

31028139 is a deficient number, since it is larger than the sum of its proper divisors (15032421).

31028139 is a wasteful number, since it uses less digits than its factorization.

31028139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 731 (or 728 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 31028139 is about 5570.2907464512. The cubic root of 31028139 is about 314.2330852154.

The spelling of 31028139 in words is "thirty-one million, twenty-eight thousand, one hundred thirty-nine".