31081925 has 18 divisors (see below), whose sum is σ = 44835858. Its totient is φ = 21312480.

The previous prime is 31081907. The next prime is 31081931. The reversal of 31081925 is 52918013.

31081925 = 1103² + 1104² + ... + 1127².

It can be written as a sum of positive squares in 3 ways, for example, as 268324 + 30813601 = 518^2 + 5551^2 .

It is not a de Polignac number, because 31081925 - 2⁸ = 31081669 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 11462 + ... + 13911.

It is an arithmetic number, because the mean of its divisors is an integer number (2490881).

Almost surely, 2^31081925 is an apocalyptic number.

31081925 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

31081925 is a deficient number, since it is larger than the sum of its proper divisors (13753933).

31081925 is a wasteful number, since it uses less digits than its factorization.

31081925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25397 (or 25385 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 31081925 is about 5575.1165907091. The cubic root of 31081925 is about 314.4145504352.

Adding to 31081925 its reverse (52918013), we get a palindrome (83999938).

The spelling of 31081925 in words is "thirty-one million, eighty-one thousand, nine hundred twenty-five".