199979623 has 2 divisors, whose sum is σ = 199979624. Its totient is φ = 199979622.

The previous prime is 199979599. The next prime is 199979629. The reversal of 199979623 is 326979991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 199979623 - 2²¹ = 197882471 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199979629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99989811 + 99989812.

It is an arithmetic number, because the mean of its divisors is an integer number (99989812).

Almost surely, 2^199979623 is an apocalyptic number.

199979623 is a deficient number, since it is larger than the sum of its proper divisors (1).

199979623 is an equidigital number, since it uses as much as digits as its factorization.

199979623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1653372, while the sum is 55.

The square root of 199979623 is about 14141.4151696356. The cubic root of 199979623 is about 584.7836860649.

The spelling of 199979623 in words is "one hundred ninety-nine million, nine hundred seventy-nine thousand, six hundred twenty-three".