649785840 has 80 divisors (see below), whose sum is σ = 2197466496. Its totient is φ = 157523200.

The previous prime is 649785839. The next prime is 649785853. The reversal of 649785840 is 48587946.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 120426 + ... + 125705.

Almost surely, 2^649785840 is an apocalyptic number.

649785840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

649785840 is an abundant number, since it is smaller than the sum of its proper divisors (1547680656).

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

649785840 is a wasteful number, since it uses less digits than its factorization.

649785840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246158 (or 246152 counting only the distinct ones).

The product of its (nonzero) digits is 1935360, while the sum is 51.

The square root of 649785840 is about 25490.8971988041. The cubic root of 649785840 is about 866.1439596257.

The spelling of 649785840 in words is "six hundred forty-nine million, seven hundred eighty-five thousand, eight hundred forty".