221992679 has 2 divisors, whose sum is σ = 221992680. Its totient is φ = 221992678.

The previous prime is 221992649. The next prime is 221992691. The reversal of 221992679 is 976299122.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221992679 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221992649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110996339 + 110996340.

It is an arithmetic number, because the mean of its divisors is an integer number (110996340).

Almost surely, 2^221992679 is an apocalyptic number.

221992679 is a deficient number, since it is larger than the sum of its proper divisors (1).

221992679 is an equidigital number, since it uses as much as digits as its factorization.

221992679 is an evil number, because the sum of its binary digits is even.

The product of its digits is 244944, while the sum is 47.

The square root of 221992679 is about 14899.4187470518. The cubic root of 221992679 is about 605.4982385699.

The spelling of 221992679 in words is "two hundred twenty-one million, nine hundred ninety-two thousand, six hundred seventy-nine".