90420205 has 4 divisors (see below), whose sum is σ = 108504252. Its totient is φ = 72336160.

The previous prime is 90420167. The next prime is 90420217. The reversal of 90420205 is 50202409.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 30404196 + 60016009 = 5514^2 + 7747^2 .

It is not a de Polignac number, because 90420205 - 2²⁵ = 56865773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9042016 + ... + 9042025.

It is an arithmetic number, because the mean of its divisors is an integer number (27126063).

Almost surely, 2^90420205 is an apocalyptic number.

It is an amenable number.

90420205 is a deficient number, since it is larger than the sum of its proper divisors (18084047).

90420205 is a wasteful number, since it uses less digits than its factorization.

90420205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18084046.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 90420205 is about 9508.9539382626. The cubic root of 90420205 is about 448.8368396742.

The spelling of 90420205 in words is "ninety million, four hundred twenty thousand, two hundred five".