31681340 has 24 divisors (see below), whose sum is σ = 68826240. Its totient is φ = 12235328.

The previous prime is 31681301. The next prime is 31681367. The reversal of 31681340 is 4318613.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26732 + ... + 27891.

It is an arithmetic number, because the mean of its divisors is an integer number (2867760).

Almost surely, 2^31681340 is an apocalyptic number.

It is an amenable number.

31681340 is an abundant number, since it is smaller than the sum of its proper divisors (37144900).

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

31681340 is a wasteful number, since it uses less digits than its factorization.

31681340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54661 (or 54659 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 31681340 is about 5628.6179475960. The cubic root of 31681340 is about 316.4228569620.

Adding to 31681340 its reverse (4318613), we get a palindrome (35999953).

The spelling of 31681340 in words is "thirty-one million, six hundred eighty-one thousand, three hundred forty".