31331020 has 48 divisors (see below), whose sum is σ = 77797440. Its totient is φ = 10370304.

The previous prime is 31330993. The next prime is 31331023. The reversal of 31331020 is 2013313.

It is not an unprimeable number, because it can be changed into a prime (31331023) by changing a digit.

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, 202 + ... + 7918.

It is an arithmetic number, because the mean of its divisors is an integer number (1620780).

Almost surely, 2^31331020 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31331020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38898720).

31331020 is an abundant number, since it is smaller than the sum of its proper divisors (46466420).

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

31331020 is a wasteful number, since it uses less digits than its factorization.

31331020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7762 (or 7760 counting only the distinct ones).

The product of its (nonzero) digits is 54, while the sum is 13.

The square root of 31331020 is about 5597.4119019418. The cubic root of 31331020 is about 315.2522377069.

Adding to 31331020 its reverse (2013313), we get a palindrome (33344333).

The spelling of 31331020 in words is "thirty-one million, three hundred thirty-one thousand, twenty".