221713686 has 64 divisors (see below), whose sum is σ = 503375040. Its totient is φ = 73226592.

The previous prime is 221713669. The next prime is 221713693. The reversal of 221713686 is 686317122.

221713686 is a `hidden beast` number, since 221 + 71 + 368 + 6 = 666.

221713686 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 221713686.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 756556 + ... + 756848.

It is an arithmetic number, because the mean of its divisors is an integer number (7865235).

Almost surely, 2^221713686 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221713686, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (251687520).

221713686 is an abundant number, since it is smaller than the sum of its proper divisors (281661354).

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

221713686 is an equidigital number, since it uses as much as digits as its factorization.

221713686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 489 (or 471 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 221713686 is about 14890.0532571244. The cubic root of 221713686 is about 605.2444755649.

The spelling of 221713686 in words is "two hundred twenty-one million, seven hundred thirteen thousand, six hundred eighty-six".