221590871 has 4 divisors (see below), whose sum is σ = 221859000. Its totient is φ = 221322744.

The previous prime is 221590867. The next prime is 221590931. The reversal of 221590871 is 178095122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 221590871 - 2² = 221590867 is a prime.

It is a super-2 number, since 2×221590871² = 98205028221077282, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221590841) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 132821 + ... + 134478.

It is an arithmetic number, because the mean of its divisors is an integer number (55464750).

Almost surely, 2^221590871 is an apocalyptic number.

221590871 is a deficient number, since it is larger than the sum of its proper divisors (268129).

221590871 is an equidigital number, since it uses as much as digits as its factorization.

221590871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268128.

The product of its (nonzero) digits is 10080, while the sum is 35.

The square root of 221590871 is about 14885.9286240395. The cubic root of 221590871 is about 605.1326995306.

The spelling of 221590871 in words is "two hundred twenty-one million, five hundred ninety thousand, eight hundred seventy-one".