217685420760 has 32 divisors (see below), whose sum is σ = 653056262640. Its totient is φ = 58049445504.

The previous prime is 217685420723. The next prime is 217685420773. The reversal of 217685420760 is 67024586712.

It is a super-2 number, since 2×217685420760² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

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, 907022467 + ... + 907022706.

Almost surely, 2^217685420760 is an apocalyptic number.

217685420760 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217685420760 is an abundant number, since it is smaller than the sum of its proper divisors (435370841880).

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

217685420760 is a wasteful number, since it uses less digits than its factorization.

217685420760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1814045187 (or 1814045183 counting only the distinct ones).

The product of its (nonzero) digits is 1128960, while the sum is 48.

The spelling of 217685420760 in words is "two hundred seventeen billion, six hundred eighty-five million, four hundred twenty thousand, seven hundred sixty".