217149220 has 24 divisors (see below), whose sum is σ = 456499008. Its totient is φ = 86767200.

The previous prime is 217149217. The next prime is 217149239. The reversal of 217149220 is 22941712.

217149220 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15355 + ... + 25885.

It is an arithmetic number, because the mean of its divisors is an integer number (19020792).

Almost surely, 2^217149220 is an apocalyptic number.

217149220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217149220 is an abundant number, since it is smaller than the sum of its proper divisors (239349788).

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

217149220 is a wasteful number, since it uses less digits than its factorization.

217149220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11571 (or 11569 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 217149220 is about 14735.9838490682. The cubic root of 217149220 is about 601.0622109959.

The spelling of 217149220 in words is "two hundred seventeen million, one hundred forty-nine thousand, two hundred twenty".