90404640409 has 4 divisors (see below), whose sum is σ = 90405254016. Its totient is φ = 90404026804.

The previous prime is 90404640407. The next prime is 90404640427.

It is a happy number.

90404640409 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 90404640409 - 2¹ = 90404640407 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90404640407) 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, 61872 + ... + 429694.

It is an arithmetic number, because the mean of its divisors is an integer number (22601313504).

Almost surely, 2^90404640409 is an apocalyptic number.

It is an amenable number.

90404640409 is a deficient number, since it is larger than the sum of its proper divisors (613607).

90404640409 is a wasteful number, since it uses less digits than its factorization.

90404640409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 613606.

The product of its (nonzero) digits is 124416, while the sum is 40.

The spelling of 90404640409 in words is "ninety billion, four hundred four million, six hundred forty thousand, four hundred nine".