31200120 has 128 divisors (see below), whose sum is σ = 118886400. Its totient is φ = 7129728.

The previous prime is 31200089. The next prime is 31200137. The reversal of 31200120 is 2100213.

It is a happy number.

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

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

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 31 ways as a sum of consecutive naturals, for example, 5497 + ... + 9623.

It is an arithmetic number, because the mean of its divisors is an integer number (928800).

Almost surely, 2^31200120 is an apocalyptic number.

31200120 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 31200120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (59443200).

31200120 is an abundant number, since it is smaller than the sum of its proper divisors (87686280).

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

31200120 is a wasteful number, since it uses less digits than its factorization.

31200120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4154 (or 4144 counting only the distinct ones).

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

The square root of 31200120 is about 5585.7067592204. The cubic root of 31200120 is about 314.8125869311.

Adding to 31200120 its reverse (2100213), we get a palindrome (33300333).

The spelling of 31200120 in words is "thirty-one million, two hundred thousand, one hundred twenty".