649293821 has 16 divisors (see below), whose sum is σ = 757838400. Its totient is φ = 550022400.

The previous prime is 649293787. The next prime is 649293823. The reversal of 649293821 is 128392946.

It is a cyclic number.

It is not a de Polignac number, because 649293821 - 2¹⁰ = 649292797 is a prime.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649293823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12716 + ... + 38213.

It is an arithmetic number, because the mean of its divisors is an integer number (47364900).

Almost surely, 2^649293821 is an apocalyptic number.

649293821 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

649293821 is a deficient number, since it is larger than the sum of its proper divisors (108544579).

649293821 is a wasteful number, since it uses less digits than its factorization.

649293821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51020.

The product of its digits is 186624, while the sum is 44.

The square root of 649293821 is about 25481.2444947259. The cubic root of 649293821 is about 865.9252891721.

The spelling of 649293821 in words is "six hundred forty-nine million, two hundred ninety-three thousand, eight hundred twenty-one".