31129225 has 6 divisors (see below), whose sum is σ = 38600270. Its totient is φ = 24903360.

The previous prime is 31129213. The next prime is 31129237. The reversal of 31129225 is 52292113.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (31129213) and next prime (31129237).

It can be written as a sum of positive squares in 3 ways, for example, as 9114361 + 22014864 = 3019^2 + 4692^2 .

It is not a de Polignac number, because 31129225 - 2¹¹ = 31127177 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25), and also a Moran number because the ratio is a prime number: 1245169 = 31129225 / (3 + 1 + 1 + 2 + 9 + 2 + 2 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 31129225.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 622560 + ... + 622609.

Almost surely, 2^31129225 is an apocalyptic number.

It is an amenable number.

31129225 is a deficient number, since it is larger than the sum of its proper divisors (7471045).

31129225 is a wasteful number, since it uses less digits than its factorization.

31129225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1245179 (or 1245174 counting only the distinct ones).

The product of its digits is 1080, while the sum is 25.

The square root of 31129225 is about 5579.3570418105. The cubic root of 31129225 is about 314.5739600246.

The spelling of 31129225 in words is "thirty-one million, one hundred twenty-nine thousand, two hundred twenty-five".