31080720 has 160 divisors (see below), whose sum is σ = 107385984. Its totient is φ = 7372800.

The previous prime is 31080689. The next prime is 31080757. The reversal of 31080720 is 2708013.

It is a super-2 number, since 2×31080720² = 1932022311436800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 160944 + ... + 161136.

Almost surely, 2^31080720 is an apocalyptic number.

31080720 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 31080720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (53692992).

31080720 is an abundant number, since it is smaller than the sum of its proper divisors (76305264).

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

31080720 is a wasteful number, since it uses less digits than its factorization.

31080720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 281 (or 275 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 21.

The square root of 31080720 is about 5575.0085201729. The cubic root of 31080720 is about 314.4104872545.

Adding to 31080720 its reverse (2708013), we get a palindrome (33788733).

The spelling of 31080720 in words is "thirty-one million, eighty thousand, seven hundred twenty".