221715 has 24 divisors (see below), whose sum is σ = 414960. Its totient is φ = 108864.

The previous prime is 221713. The next prime is 221717. The reversal of 221715 is 517122.

It is an interprime number because it is at equal distance from previous prime (221713) and next prime (221717).

It is not a de Polignac number, because 221715 - 2¹ = 221713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221713) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 396 + ... + 774.

It is an arithmetic number, because the mean of its divisors is an integer number (17290).

2²²¹⁷¹⁵ is an apocalyptic number.

221715 is a deficient number, since it is larger than the sum of its proper divisors (193245).

221715 is a wasteful number, since it uses less digits than its factorization.

221715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 403 (or 400 counting only the distinct ones).

The product of its digits is 140, while the sum is 18.

The square root of 221715 is about 470.8662230400. The cubic root of 221715 is about 60.5245671236.

Adding to 221715 its reverse (517122), we get a palindrome (738837).

The spelling of 221715 in words is "two hundred twenty-one thousand, seven hundred fifteen".