18772220 has 12 divisors (see below), whose sum is σ = 39421704. Its totient is φ = 7508880.

The previous prime is 18772183. The next prime is 18772277. The reversal of 18772220 is 2227781.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 469286 + ... + 469325.

It is an arithmetic number, because the mean of its divisors is an integer number (3285142).

Almost surely, 2^18772220 is an apocalyptic number.

18772220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18772220 is an abundant number, since it is smaller than the sum of its proper divisors (20649484).

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

18772220 is a wasteful number, since it uses less digits than its factorization.

18772220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 938620 (or 938618 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 29.

The square root of 18772220 is about 4332.6920038240. The cubic root of 18772220 is about 265.7695443053.

The spelling of 18772220 in words is "eighteen million, seven hundred seventy-two thousand, two hundred twenty".