90571709 has 4 divisors (see below), whose sum is σ = 90659100. Its totient is φ = 90484320.

The previous prime is 90571601. The next prime is 90571721. The reversal of 90571709 is 90717509.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90717509 = 2213 ⋅40993.

It can be written as a sum of positive squares in 2 ways, for example, as 55204900 + 35366809 = 7430^2 + 5947^2 .

It is a cyclic number.

It is not a de Polignac number, because 90571709 - 2¹² = 90567613 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90571729) 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, 42122 + ... + 44219.

It is an arithmetic number, because the mean of its divisors is an integer number (22664775).

Almost surely, 2^90571709 is an apocalyptic number.

It is an amenable number.

90571709 is a deficient number, since it is larger than the sum of its proper divisors (87391).

90571709 is a wasteful number, since it uses less digits than its factorization.

90571709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87390.

The product of its (nonzero) digits is 19845, while the sum is 38.

The square root of 90571709 is about 9516.9169902863. The cubic root of 90571709 is about 449.0873833527.

The spelling of 90571709 in words is "ninety million, five hundred seventy-one thousand, seven hundred nine".