18640422 has 16 divisors (see below), whose sum is σ = 41423280. Its totient is φ = 6213456.

The previous prime is 18640421. The next prime is 18640429. The reversal of 18640422 is 22404681.

18640422 is a `hidden beast` number, since 18 + 640 + 4 + 2 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18640421) 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, 172543 + ... + 172650.

It is an arithmetic number, because the mean of its divisors is an integer number (2588955).

Almost surely, 2^18640422 is an apocalyptic number.

18640422 is an abundant number, since it is smaller than the sum of its proper divisors (22782858).

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

18640422 is a wasteful number, since it uses less digits than its factorization.

18640422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 345204 (or 345198 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 18640422 is about 4317.4555006392. The cubic root of 18640422 is about 265.1461019437.

The spelling of 18640422 in words is "eighteen million, six hundred forty thousand, four hundred twenty-two".