221147999 has 2 divisors, whose sum is σ = 221148000. Its totient is φ = 221147998.

The previous prime is 221147977. The next prime is 221148007. The reversal of 221147999 is 999741122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221147999 - 2⁸ = 221147743 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221147909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110573999 + 110574000.

It is an arithmetic number, because the mean of its divisors is an integer number (110574000).

Almost surely, 2^221147999 is an apocalyptic number.

221147999 is a deficient number, since it is larger than the sum of its proper divisors (1).

221147999 is an equidigital number, since it uses as much as digits as its factorization.

221147999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81648, while the sum is 44.

The square root of 221147999 is about 14871.0456592669. The cubic root of 221147999 is about 604.7292908138.

The spelling of 221147999 in words is "two hundred twenty-one million, one hundred forty-seven thousand, nine hundred ninety-nine".