18641220 has 48 divisors (see below), whose sum is σ = 56212800. Its totient is φ = 4588416.

The previous prime is 18641167. The next prime is 18641251. The reversal of 18641220 is 2214681.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11170 + ... + 12729.

It is an arithmetic number, because the mean of its divisors is an integer number (1171100).

Almost surely, 2^18641220 is an apocalyptic number.

18641220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18641220 is an abundant number, since it is smaller than the sum of its proper divisors (37571580).

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

18641220 is a wasteful number, since it uses less digits than its factorization.

18641220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23924 (or 23922 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 18641220 is about 4317.5479151945. The cubic root of 18641220 is about 265.1498855413.

The spelling of 18641220 in words is "eighteen million, six hundred forty-one thousand, two hundred twenty".