649696720 has 20 divisors (see below), whose sum is σ = 1510545060. Its totient is φ = 259878656.

The previous prime is 649696699. The next prime is 649696739. The reversal of 649696720 is 27696946.

649696720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 261921856 + 387774864 = 16184^2 + 19692^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4060525 + ... + 4060684.

It is an arithmetic number, because the mean of its divisors is an integer number (75527253).

Almost surely, 2^649696720 is an apocalyptic number.

It is an amenable number.

649696720 is an abundant number, since it is smaller than the sum of its proper divisors (860848340).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

649696720 is a wasteful number, since it uses less digits than its factorization.

649696720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8121222 (or 8121216 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 49.

The square root of 649696720 is about 25489.1490638664. The cubic root of 649696720 is about 866.1043597687.

The spelling of 649696720 in words is "six hundred forty-nine million, six hundred ninety-six thousand, seven hundred twenty".