217157212 has 24 divisors (see below), whose sum is σ = 385862400. Its totient is φ = 106923456.

The previous prime is 217157207. The next prime is 217157221. The reversal of 217157212 is 212751712.

It is a super-2 number, since 2×217157212² = 94314509447225888, which contains 22 as substring.

It is a congruent number.

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, 73989 + ... + 76867.

It is an arithmetic number, because the mean of its divisors is an integer number (16077600).

Almost surely, 2^217157212 is an apocalyptic number.

It is an amenable number.

217157212 is a deficient number, since it is larger than the sum of its proper divisors (168705188).

217157212 is a wasteful number, since it uses less digits than its factorization.

217157212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3165 (or 3163 counting only the distinct ones).

The product of its digits is 1960, while the sum is 28.

The square root of 217157212 is about 14736.2550195089. The cubic root of 217157212 is about 601.0695847736.

The spelling of 217157212 in words is "two hundred seventeen million, one hundred fifty-seven thousand, two hundred twelve".