90197172780 has 576 divisors, whose sum is σ = 317570803200. Its totient is φ = 18947174400.

The previous prime is 90197172617. The next prime is 90197172781. The reversal of 90197172780 is 8727179109.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (90197172781) by changing a digit.

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 191 ways as a sum of consecutive naturals, for example, 320986240 + ... + 320986520.

It is an arithmetic number, because the mean of its divisors is an integer number (551338200).

Almost surely, 2^90197172780 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 90197172780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (158785401600).

90197172780 is an abundant number, since it is smaller than the sum of its proper divisors (227373630420).

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

90197172780 is a wasteful number, since it uses less digits than its factorization.

90197172780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 526 (or 513 counting only the distinct ones).

The product of its (nonzero) digits is 444528, while the sum is 51.

The spelling of 90197172780 in words is "ninety billion, one hundred ninety-seven million, one hundred seventy-two thousand, seven hundred eighty".