649920040 has 96 divisors (see below), whose sum is σ = 1837059840. Its totient is φ = 202561920.

The previous prime is 649920031. The next prime is 649920041. The reversal of 649920040 is 40029946.

It is a junction number, because it is equal to n+sod(n) for n = 649919978 and 649920005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649920041) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 24289 + ... + 43471.

It is an arithmetic number, because the mean of its divisors is an integer number (19136040).

Almost surely, 2^649920040 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 649920040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (918529920).

649920040 is an abundant number, since it is smaller than the sum of its proper divisors (1187139800).

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

649920040 is a wasteful number, since it uses less digits than its factorization.

649920040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19223 (or 19208 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 649920040 is about 25493.5293751179. The cubic root of 649920040 is about 866.2035836387.

Adding to 649920040 its reverse (40029946), we get a palindrome (689949986).

The spelling of 649920040 in words is "six hundred forty-nine million, nine hundred twenty thousand, forty".