90209520 has 120 divisors (see below), whose sum is σ = 304668000. Its totient is φ = 23920128.

The previous prime is 90209513. The next prime is 90209533. The reversal of 90209520 is 2590209.

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

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 23 ways as a sum of consecutive naturals, for example, 251101 + ... + 251459.

It is an arithmetic number, because the mean of its divisors is an integer number (2538900).

Almost surely, 2^90209520 is an apocalyptic number.

90209520 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 90209520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (152334000).

90209520 is an abundant number, since it is smaller than the sum of its proper divisors (214458480).

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

90209520 is a wasteful number, since it uses less digits than its factorization.

90209520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 727 (or 718 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 90209520 is about 9497.8692347284. The cubic root of 90209520 is about 448.4879621531.

Adding to 90209520 its reverse (2590209), we get a palindrome (92799729).

The spelling of 90209520 in words is "ninety million, two hundred nine thousand, five hundred twenty".