90721332 has 72 divisors (see below), whose sum is σ = 248812200. Its totient is φ = 27705600.

The previous prime is 90721313. The next prime is 90721339. The reversal of 90721332 is 23312709.

It can be written as a sum of positive squares in 4 ways, for example, as 13351716 + 77369616 = 3654^2 + 8796^2 .

It is a junction number, because it is equal to n+sod(n) for n = 90721296 and 90721305.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90721339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 69082 + ... + 70382.

It is an arithmetic number, because the mean of its divisors is an integer number (3455725).

Almost surely, 2^90721332 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 90721332, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124406100).

90721332 is an abundant number, since it is smaller than the sum of its proper divisors (158090868).

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

90721332 is a wasteful number, since it uses less digits than its factorization.

90721332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1473 (or 1468 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 27.

The square root of 90721332 is about 9524.7746430034. The cubic root of 90721332 is about 449.3345423357.

It can be divided in two parts, 9072 and 1332, that added together give a square (10404 = 102²).

The spelling of 90721332 in words is "ninety million, seven hundred twenty-one thousand, three hundred thirty-two".