90300809 has 4 divisors (see below), whose sum is σ = 93414660. Its totient is φ = 87186960.

The previous prime is 90300803. The next prime is 90300811. The reversal of 90300809 is 90800309.

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 24285184 + 66015625 = 4928^2 + 8125^2 .

It is a cyclic number.

It is not a de Polignac number, because 90300809 - 2¹⁶ = 90235273 is a prime.

It is a super-2 number, since 2×90300809² = 16308472212108962, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29), and also a Moran number because the ratio is a prime number: 3113821 = 90300809 / (9 + 0 + 3 + 0 + 0 + 8 + 0 + 9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90300803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1556882 + ... + 1556939.

It is an arithmetic number, because the mean of its divisors is an integer number (23353665).

Almost surely, 2^90300809 is an apocalyptic number.

It is an amenable number.

90300809 is a deficient number, since it is larger than the sum of its proper divisors (3113851).

90300809 is a wasteful number, since it uses less digits than its factorization.

90300809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3113850.

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 90300809 is about 9502.6737816259. The cubic root of 90300809 is about 448.6391960609.

Subtracting 90300809 from its reverse (90800309), we obtain a triangular number (499500 = T₉₉₉).

The spelling of 90300809 in words is "ninety million, three hundred thousand, eight hundred nine".