31661340 has 48 divisors (see below), whose sum is σ = 92510208. Its totient is φ = 8075584.

The previous prime is 31661309. The next prime is 31661351. The reversal of 31661340 is 4316613.

It is a self number, because there is not a number n which added to its sum of digits gives 31661340.

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 15 ways as a sum of consecutive naturals, for example, 10092 + ... + 12851.

It is an arithmetic number, because the mean of its divisors is an integer number (1927296).

Almost surely, 2^31661340 is an apocalyptic number.

31661340 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31661340 is an abundant number, since it is smaller than the sum of its proper divisors (60848868).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31661340 is a wasteful number, since it uses less digits than its factorization.

31661340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22978 (or 22976 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 24.

The square root of 31661340 is about 5626.8410320534. The cubic root of 31661340 is about 316.3562584606.

Adding to 31661340 its reverse (4316613), we get a palindrome (35977953).

The spelling of 31661340 in words is "thirty-one million, six hundred sixty-one thousand, three hundred forty".