90720 has 120 divisors (see below), whose sum is σ = 365904. Its totient is φ = 20736.

The previous prime is 90709. The next prime is 90731. The reversal of 90720 is 2709.

It is an interprime number because it is at equal distance from previous prime (90709) and next prime (90731).

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 90693 and 90702.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 12957 + ... + 12963.

2⁹⁰⁷²⁰ is an apocalyptic number.

90720 is a gapful number since it is divisible by the number (90) 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 90720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (182952).

90720 is an abundant number, since it is smaller than the sum of its proper divisors (275184).

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

90720 is a wasteful number, since it uses less digits than its factorization.

90720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34 (or 17 counting only the distinct ones).

The product of its (nonzero) digits is 126, while the sum is 18.

The square root of 90720 is about 301.1976095523. The cubic root of 90720 is about 44.9332343233.

The spelling of 90720 in words is "ninety thousand, seven hundred twenty".