90811219801 has 3 divisors (see below), whose sum is σ = 90811521151. Its totient is φ = 90810918452.

The previous prime is 90811219789. The next prime is 90811219897. The reversal of 90811219801 is 10891211809.

The square root of 90811219801 is 301349.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 67834723401 + 22976496400 = 260451^2 + 151580^2 .

It is not a de Polignac number, because 90811219801 - 2³¹ = 88663736153 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90811219001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 150675 + ... + 452023.

Almost surely, 2^90811219801 is an apocalyptic number.

90811219801 is the 301349-th square number.

90811219801 is the 150675-th centered octagonal number.

It is an amenable number.

90811219801 is a deficient number, since it is larger than the sum of its proper divisors (301350).

90811219801 is an frugal number, since it uses more digits than its factorization.

90811219801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 602698 (or 301349 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 40.

The spelling of 90811219801 in words is "ninety billion, eight hundred eleven million, two hundred nineteen thousand, eight hundred one".