221030639 has 2 divisors, whose sum is σ = 221030640. Its totient is φ = 221030638.

The previous prime is 221030627. The next prime is 221030647. The reversal of 221030639 is 936030122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221030639 - 2¹² = 221026543 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221030609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110515319 + 110515320.

It is an arithmetic number, because the mean of its divisors is an integer number (110515320).

Almost surely, 2^221030639 is an apocalyptic number.

221030639 is a deficient number, since it is larger than the sum of its proper divisors (1).

221030639 is an equidigital number, since it uses as much as digits as its factorization.

221030639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 26.

The square root of 221030639 is about 14867.0992126911. The cubic root of 221030639 is about 604.6222982296.

The spelling of 221030639 in words is "two hundred twenty-one million, thirty thousand, six hundred thirty-nine".