18649220 has 24 divisors (see below), whose sum is σ = 39571224. Its totient is φ = 7382016.

The previous prime is 18649207. The next prime is 18649223. The reversal of 18649220 is 2294681.

It can be written as a sum of positive squares in 4 ways, for example, as 6980164 + 11669056 = 2642^2 + 3416^2 .

It is not an unprimeable number, because it can be changed into a prime (18649223) 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, 2867 + ... + 6746.

It is an arithmetic number, because the mean of its divisors is an integer number (1648801).

Almost surely, 2^18649220 is an apocalyptic number.

18649220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18649220 is an abundant number, since it is smaller than the sum of its proper divisors (20922004).

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

18649220 is a wasteful number, since it uses less digits than its factorization.

18649220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9719 (or 9717 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 18649220 is about 4318.4742676089. The cubic root of 18649220 is about 265.1878103788.

The spelling of 18649220 in words is "eighteen million, six hundred forty-nine thousand, two hundred twenty".