31440625 has 12 divisors (see below), whose sum is σ = 39302172. Its totient is φ = 25150000.

The previous prime is 31440623. The next prime is 31440641. The reversal of 31440625 is 52604413.

It can be written as a sum of positive squares in 6 ways, for example, as 25070049 + 6370576 = 5007^2 + 2524^2 .

It is not a de Polignac number, because 31440625 - 2¹ = 31440623 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31440625.

It is not an unprimeable number, because it can be changed into a prime (31440623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1906 + ... + 8155.

It is an arithmetic number, because the mean of its divisors is an integer number (3275181).

Almost surely, 2^31440625 is an apocalyptic number.

It is an amenable number.

31440625 is a deficient number, since it is larger than the sum of its proper divisors (7861547).

31440625 is an frugal number, since it uses more digits than its factorization.

31440625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10086 (or 10066 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 31440625 is about 5607.1940398028. The cubic root of 31440625 is about 315.6194244677.

The spelling of 31440625 in words is "thirty-one million, four hundred forty thousand, six hundred twenty-five".