219649249891 has 2 divisors, whose sum is σ = 219649249892. Its totient is φ = 219649249890.

The previous prime is 219649249889. The next prime is 219649249957. The reversal of 219649249891 is 198942946912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 219649249891 - 2¹ = 219649249889 is a prime.

Together with 219649249889, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (219649249091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109824624945 + 109824624946.

It is an arithmetic number, because the mean of its divisors is an integer number (109824624946).

Almost surely, 2^219649249891 is an apocalyptic number.

219649249891 is a deficient number, since it is larger than the sum of its proper divisors (1).

219649249891 is an equidigital number, since it uses as much as digits as its factorization.

219649249891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20155392, while the sum is 64.

The spelling of 219649249891 in words is "two hundred nineteen billion, six hundred forty-nine million, two hundred forty-nine thousand, eight hundred ninety-one".