221917087 has 12 divisors (see below), whose sum is σ = 265130320. Its totient is φ = 181941408.

The previous prime is 221917081. The next prime is 221917181. The reversal of 221917087 is 780719122.

It is not a de Polignac number, because 221917087 - 2³ = 221917079 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221917081) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26262 + ... + 33667.

Almost surely, 2^221917087 is an apocalyptic number.

221917087 is a deficient number, since it is larger than the sum of its proper divisors (43213233).

221917087 is an equidigital number, since it uses as much as digits as its factorization.

221917087 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59982 (or 59959 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 37.

The square root of 221917087 is about 14896.8817878105. The cubic root of 221917087 is about 605.4295035419.

It can be divided in two parts, 2219 and 17087, that added together give a triangular number (19306 = T₁₉₆).

The spelling of 221917087 in words is "two hundred twenty-one million, nine hundred seventeen thousand, eighty-seven".