199664497 has 2 divisors, whose sum is σ = 199664498.
Its totient is φ = 199664496.
The previous prime is 199664467. The next prime is 199664501. The reversal of 199664497 is 794466991.
It is a happy number.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 190688481 + 8976016 = 13809^2 + 2996^2
It is a cyclic number.
It is not a de Polignac number, because 199664497 - 227 = 65446769 is a prime.
It is a super-2 number, since 2×1996644972 = 79731822724526018, which contains 22 as substring.
It is not a weakly prime, because it can be changed into another prime (199664467) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99832248 + 99832249.
It is an arithmetic number, because the mean of its divisors is an integer number (99832249).
Almost surely, 2199664497 is an apocalyptic number.
It is an amenable number.
199664497 is a deficient number, since it is larger than the sum of its proper divisors (1).
199664497 is an equidigital number, since it uses as much as digits as its factorization.
199664497 is an evil number, because the sum of its binary digits is even.
The product of its digits is 2939328, while the sum is 55.
The square root of 199664497 is about 14130.2688226375.
The cubic root of 199664497 is about 584.4763590453.
The spelling of 199664497 in words is "one hundred ninety-nine million, six hundred sixty-four thousand, four hundred ninety-seven".