90991020 has 48 divisors (see below), whose sum is σ = 257130720. Its totient is φ = 24039936.

The previous prime is 90990997. The next prime is 90991027. The reversal of 90991020 is 2019909.

It is a super-4 number, since 4×90991020⁴ (a number of 33 digits) contains 4444 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (90991027) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 417 + ... + 13496.

It is an arithmetic number, because the mean of its divisors is an integer number (5356890).

Almost surely, 2^90991020 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 90991020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128565360).

90991020 is an abundant number, since it is smaller than the sum of its proper divisors (166139700).

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

90991020 is a wasteful number, since it uses less digits than its factorization.

90991020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14034 (or 14032 counting only the distinct ones).

The product of its (nonzero) digits is 1458, while the sum is 30.

The square root of 90991020 is about 9538.9213226654. The cubic root of 90991020 is about 449.7793486144.

The spelling of 90991020 in words is "ninety million, nine hundred ninety-one thousand, twenty".