649217640 has 64 divisors (see below), whose sum is σ = 1950220800. Its totient is φ = 172896512.

The previous prime is 649217633. The next prime is 649217659. The reversal of 649217640 is 46712946.

It is a happy number.

649217640 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 100426 + ... + 106694.

It is an arithmetic number, because the mean of its divisors is an integer number (30472200).

Almost surely, 2^649217640 is an apocalyptic number.

649217640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

649217640 is an abundant number, since it is smaller than the sum of its proper divisors (1301003160).

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

649217640 is a wasteful number, since it uses less digits than its factorization.

649217640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7146 (or 7142 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 39.

The square root of 649217640 is about 25479.7496063050. The cubic root of 649217640 is about 865.8914217958.

The spelling of 649217640 in words is "six hundred forty-nine million, two hundred seventeen thousand, six hundred forty".