221302987 has 4 divisors (see below), whose sum is σ = 230924880. Its totient is φ = 211681096.

The previous prime is 221302979. The next prime is 221302993. The reversal of 221302987 is 789203122.

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 221302987 - 2³ = 221302979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221302927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4810912 + ... + 4810957.

It is an arithmetic number, because the mean of its divisors is an integer number (57731220).

Almost surely, 2^221302987 is an apocalyptic number.

221302987 is a deficient number, since it is larger than the sum of its proper divisors (9621893).

221302987 is an equidigital number, since it uses as much as digits as its factorization.

221302987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9621892.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 221302987 is about 14876.2558125356. The cubic root of 221302987 is about 604.8705294065.

The spelling of 221302987 in words is "two hundred twenty-one million, three hundred two thousand, nine hundred eighty-seven".