31130257 has 4 divisors (see below), whose sum is σ = 31405860. Its totient is φ = 30854656.

The previous prime is 31130251. The next prime is 31130261. The reversal of 31130257 is 75203113.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75203113 = 6841 ⋅10993.

It can be written as a sum of positive squares in 2 ways, for example, as 1547536 + 29582721 = 1244^2 + 5439^2 .

It is a cyclic number.

It is not a de Polignac number, because 31130257 - 2¹⁹ = 30605969 is a prime.

It is a super-3 number, since 3×31130257³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31130251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 137632 + ... + 137857.

It is an arithmetic number, because the mean of its divisors is an integer number (7851465).

Almost surely, 2^31130257 is an apocalyptic number.

It is an amenable number.

31130257 is a deficient number, since it is larger than the sum of its proper divisors (275603).

31130257 is a wasteful number, since it uses less digits than its factorization.

31130257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275602.

The product of its (nonzero) digits is 630, while the sum is 22.

The square root of 31130257 is about 5579.4495248187. The cubic root of 31130257 is about 314.5774362514.

The spelling of 31130257 in words is "thirty-one million, one hundred thirty thousand, two hundred fifty-seven".