31316620 has 48 divisors (see below), whose sum is σ = 68062176. Its totient is φ = 12096000.

The previous prime is 31316581. The next prime is 31316629. The reversal of 31316620 is 2661313.

It is a junction number, because it is equal to n+sod(n) for n = 31316591 and 31316600.

It is not an unprimeable number, because it can be changed into a prime (31316629) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 148315 + ... + 148525.

It is an arithmetic number, because the mean of its divisors is an integer number (1417962).

Almost surely, 2^31316620 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 31316620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34031088).

31316620 is an abundant number, since it is smaller than the sum of its proper divisors (36745556).

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

31316620 is a wasteful number, since it uses less digits than its factorization.

31316620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 442 (or 440 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 31316620 is about 5596.1254453416. The cubic root of 31316620 is about 315.2039327801.

Adding to 31316620 its reverse (2661313), we get a palindrome (33977933).

The spelling of 31316620 in words is "thirty-one million, three hundred sixteen thousand, six hundred twenty".