90561720 has 128 divisors (see below), whose sum is σ = 291133440. Its totient is φ = 22456320.

The previous prime is 90561643. The next prime is 90561763. The reversal of 90561720 is 2716509.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

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

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, 209905 + ... + 210335.

It is an arithmetic number, because the mean of its divisors is an integer number (2274480).

Almost surely, 2^90561720 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 90561720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145566720).

90561720 is an abundant number, since it is smaller than the sum of its proper divisors (200571720).

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

90561720 is a wasteful number, since it uses less digits than its factorization.

90561720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 565 (or 561 counting only the distinct ones).

The product of its (nonzero) digits is 3780, while the sum is 30.

The square root of 90561720 is about 9516.3921735078. The cubic root of 90561720 is about 449.0708730507.

The spelling of 90561720 in words is "ninety million, five hundred sixty-one thousand, seven hundred twenty".