199976509 has 2 divisors, whose sum is σ = 199976510. Its totient is φ = 199976508.

The previous prime is 199976471. The next prime is 199976519. The reversal of 199976509 is 905679991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 163712025 + 36264484 = 12795^2 + 6022^2 .

It is an emirp because it is prime and its reverse (905679991) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199976509 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 199976509.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199976519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99988254 + 99988255.

It is an arithmetic number, because the mean of its divisors is an integer number (99988255).

Almost surely, 2^199976509 is an apocalyptic number.

It is an amenable number.

199976509 is a deficient number, since it is larger than the sum of its proper divisors (1).

199976509 is an equidigital number, since it uses as much as digits as its factorization.

199976509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1377810, while the sum is 55.

The square root of 199976509 is about 14141.3050670721. The cubic root of 199976509 is about 584.7806507125.

The spelling of 199976509 in words is "one hundred ninety-nine million, nine hundred seventy-six thousand, five hundred nine".