9090640 has 40 divisors (see below), whose sum is σ = 22764168. Its totient is φ = 3356160.

The previous prime is 9090629. The next prime is 9090649. The reversal of 9090640 is 460909.

It can be written as a sum of positive squares in 4 ways, for example, as 18496 + 9072144 = 136^2 + 3012^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 9090599 and 9090608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9090649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3331 + ... + 5410.

Almost surely, 2^9090640 is an apocalyptic number.

It is an amenable number.

9090640 is an abundant number, since it is smaller than the sum of its proper divisors (13673528).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9090640 is a wasteful number, since it uses less digits than its factorization.

9090640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8767 (or 8761 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 9090640 is about 3015.0688217684. The cubic root of 9090640 is about 208.7043429855.

It can be divided in two parts, 9090 and 640, that added together give a triangular number (9730 = T₁₃₉).

The spelling of 9090640 in words is "nine million, ninety thousand, six hundred forty".