90121728 has 80 divisors (see below), whose sum is σ = 250626816. Its totient is φ = 28723200.

The previous prime is 90121723. The next prime is 90121729. The reversal of 90121728 is 82712109.

It is a junction number, because it is equal to n+sod(n) for n = 90121695 and 90121704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90121723) 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 7 ways as a sum of consecutive naturals, for example, 34053 + ... + 36603.

Almost surely, 2^90121728 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 90121728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125313408).

90121728 is an abundant number, since it is smaller than the sum of its proper divisors (160505088).

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

90121728 is a wasteful number, since it uses less digits than its factorization.

90121728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2595 (or 2579 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 90121728 is about 9493.2464415499. The cubic root of 90121728 is about 448.3424252781.

The spelling of 90121728 in words is "ninety million, one hundred twenty-one thousand, seven hundred twenty-eight".