649738819 has 4 divisors (see below), whose sum is σ = 661998096. Its totient is φ = 637479544.

The previous prime is 649738811. The next prime is 649738847. The reversal of 649738819 is 918837946.

649738819 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 649738819 - 2³ = 649738811 is a prime.

It is a super-2 number, since 2×649738819² = 844321065831029522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 649738819.

It is not an unprimeable number, because it can be changed into a prime (649738811) 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, 6129559 + ... + 6129664.

It is an arithmetic number, because the mean of its divisors is an integer number (165499524).

Almost surely, 2^649738819 is an apocalyptic number.

649738819 is a deficient number, since it is larger than the sum of its proper divisors (12259277).

649738819 is a wasteful number, since it uses less digits than its factorization.

649738819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12259276.

The product of its digits is 2612736, while the sum is 55.

The square root of 649738819 is about 25489.9748724866. The cubic root of 649738819 is about 866.1230666201.

The spelling of 649738819 in words is "six hundred forty-nine million, seven hundred thirty-eight thousand, eight hundred nineteen".