221000999 has 4 divisors (see below), whose sum is σ = 223798560. Its totient is φ = 218203440.

The previous prime is 221000981. The next prime is 221001031. The reversal of 221000999 is 999000122.

221000999 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221000999 is a prime.

It is a Duffinian number.

221000999 is a modest number, since divided by 999 gives 221 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221000959) 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, 1398662 + ... + 1398819.

It is an arithmetic number, because the mean of its divisors is an integer number (55949640).

Almost surely, 2^221000999 is an apocalyptic number.

221000999 is a deficient number, since it is larger than the sum of its proper divisors (2797561).

221000999 is an equidigital number, since it uses as much as digits as its factorization.

221000999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2797560.

The product of its (nonzero) digits is 2916, while the sum is 32.

The square root of 221000999 is about 14866.1023472866. The cubic root of 221000999 is about 604.5952705950.

The spelling of 221000999 in words is "two hundred twenty-one million, nine hundred ninety-nine", and thus it is an aban number.