221639107 has 2 divisors, whose sum is σ = 221639108. Its totient is φ = 221639106.

The previous prime is 221639069. The next prime is 221639137. The reversal of 221639107 is 701936122.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221639107 is a prime.

It is not a weakly prime, because it can be changed into another prime (221639137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110819553 + 110819554.

It is an arithmetic number, because the mean of its divisors is an integer number (110819554).

Almost surely, 2^221639107 is an apocalyptic number.

221639107 is a deficient number, since it is larger than the sum of its proper divisors (1).

221639107 is an equidigital number, since it uses as much as digits as its factorization.

221639107 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 221639107 is about 14887.5487236818. The cubic root of 221639107 is about 605.1766048639.

The spelling of 221639107 in words is "two hundred twenty-one million, six hundred thirty-nine thousand, one hundred seven".