90401909 has 4 divisors (see below), whose sum is σ = 97355916. Its totient is φ = 83447904.

The previous prime is 90401897. The next prime is 90401911. The reversal of 90401909 is 90910409.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90910409 = 257 ⋅353737.

It can be written as a sum of positive squares in 2 ways, for example, as 57304900 + 33097009 = 7570^2 + 5753^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90401909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90401999) 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, 3476984 + ... + 3477009.

It is an arithmetic number, because the mean of its divisors is an integer number (24338979).

Almost surely, 2^90401909 is an apocalyptic number.

It is an amenable number.

90401909 is a deficient number, since it is larger than the sum of its proper divisors (6954007).

90401909 is a wasteful number, since it uses less digits than its factorization.

90401909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6954006.

The product of its (nonzero) digits is 2916, while the sum is 32.

The square root of 90401909 is about 9507.9918489658. The cubic root of 90401909 is about 448.8065644617.

The spelling of 90401909 in words is "ninety million, four hundred one thousand, nine hundred nine".