31020120 has 96 divisors (see below), whose sum is σ = 101556000. Its totient is φ = 8211456.

The previous prime is 31020107. The next prime is 31020127. The reversal of 31020120 is 2102013.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31020127) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 71424 + ... + 71856.

It is an arithmetic number, because the mean of its divisors is an integer number (1057875).

Almost surely, 2^31020120 is an apocalyptic number.

31020120 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31020120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50778000).

31020120 is an abundant number, since it is smaller than the sum of its proper divisors (70535880).

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

31020120 is a wasteful number, since it uses less digits than its factorization.

31020120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649 (or 642 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 31020120 is about 5569.5708990909. The cubic root of 31020120 is about 314.2060124539.

Adding to 31020120 its reverse (2102013), we get a palindrome (33122133).

The spelling of 31020120 in words is "thirty-one million, twenty thousand, one hundred twenty".