649198923 has 4 divisors (see below), whose sum is σ = 865598568. Its totient is φ = 432799280.

The previous prime is 649198919. The next prime is 649198933. The reversal of 649198923 is 329891946.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 649198923 - 2² = 649198919 is a prime.

It is not an unprimeable number, because it can be changed into a prime (649198933) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 108199818 + ... + 108199823.

It is an arithmetic number, because the mean of its divisors is an integer number (216399642).

Almost surely, 2^649198923 is an apocalyptic number.

649198923 is a deficient number, since it is larger than the sum of its proper divisors (216399645).

649198923 is a wasteful number, since it uses less digits than its factorization.

649198923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216399644.

The product of its digits is 839808, while the sum is 51.

The square root of 649198923 is about 25479.3823119792. The cubic root of 649198923 is about 865.8831004746.

The spelling of 649198923 in words is "six hundred forty-nine million, one hundred ninety-eight thousand, nine hundred twenty-three".