217072912 has 80 divisors (see below), whose sum is σ = 501809152. Its totient is φ = 89009280.

The previous prime is 217072907. The next prime is 217072939. The reversal of 217072912 is 219270712.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (31).

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, 357313 + ... + 357919.

Almost surely, 2^217072912 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 217072912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (250904576).

217072912 is an abundant number, since it is smaller than the sum of its proper divisors (284736240).

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

217072912 is a wasteful number, since it uses less digits than its factorization.

217072912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 756 (or 750 counting only the distinct ones).

The product of its (nonzero) digits is 3528, while the sum is 31.

The square root of 217072912 is about 14733.3944493453. The cubic root of 217072912 is about 600.9917966992.

The spelling of 217072912 in words is "two hundred seventeen million, seventy-two thousand, nine hundred twelve".