217351213920 has 576 divisors, whose sum is σ = 801644014080. Its totient is φ = 55564185600.

The previous prime is 217351213901. The next prime is 217351213927. The reversal of 217351213920 is 29312153712.

It is a happy number.

217351213920 is a `hidden beast` number, since 2 + 1 + 7 + 3 + 512 + 139 + 2 + 0 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217351213927) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 94049565 + ... + 94051875.

It is an arithmetic number, because the mean of its divisors is an integer number (1391743080).

Almost surely, 2^217351213920 is an apocalyptic number.

217351213920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 217351213920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (400822007040).

217351213920 is an abundant number, since it is smaller than the sum of its proper divisors (584292800160).

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

217351213920 is a wasteful number, since it uses less digits than its factorization.

217351213920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2441 (or 2421 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 36.

The spelling of 217351213920 in words is "two hundred seventeen billion, three hundred fifty-one million, two hundred thirteen thousand, nine hundred twenty".