31485720 has 64 divisors (see below), whose sum is σ = 107953920. Its totient is φ = 7196544.

The previous prime is 31485661. The next prime is 31485721. The reversal of 31485720 is 2758413.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31485721) 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, 17902 + ... + 19581.

It is an arithmetic number, because the mean of its divisors is an integer number (1686780).

Almost surely, 2^31485720 is an apocalyptic number.

31485720 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31485720 is an abundant number, since it is smaller than the sum of its proper divisors (76468200).

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

31485720 is a wasteful number, since it uses less digits than its factorization.

31485720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37504 (or 37500 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 31485720 is about 5611.2137724382. The cubic root of 31485720 is about 315.7702490636.

The spelling of 31485720 in words is "thirty-one million, four hundred eighty-five thousand, seven hundred twenty".