649198919 has 2 divisors, whose sum is σ = 649198920. Its totient is φ = 649198918.

The previous prime is 649198909. The next prime is 649198933. The reversal of 649198919 is 919891946.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 649198919 - 2²⁰ = 648150343 is a prime.

It is a super-2 number, since 2×649198919² = 842918472861537122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (649198909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324599459 + 324599460.

It is an arithmetic number, because the mean of its divisors is an integer number (324599460).

Almost surely, 2^649198919 is an apocalyptic number.

649198919 is a deficient number, since it is larger than the sum of its proper divisors (1).

649198919 is an equidigital number, since it uses as much as digits as its factorization.

649198919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1259712, while the sum is 56.

The square root of 649198919 is about 25479.3822334844. The cubic root of 649198919 is about 865.8830986963.

The spelling of 649198919 in words is "six hundred forty-nine million, one hundred ninety-eight thousand, nine hundred nineteen".