649179440 has 120 divisors (see below), whose sum is σ = 1890972720. Its totient is φ = 205438464.

The previous prime is 649179373. The next prime is 649179449. The reversal of 649179440 is 44971946.

It is a Cunningham number, because it is equal to 25479²-1.

It is a junction number, because it is equal to n+sod(n) for n = 649179391 and 649179400.

It is not an unprimeable number, because it can be changed into a prime (649179449) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 44591 + ... + 57329.

It is an arithmetic number, because the mean of its divisors is an integer number (15758106).

Almost surely, 2^649179440 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 649179440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (945486360).

649179440 is an abundant number, since it is smaller than the sum of its proper divisors (1241793280).

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

649179440 is a wasteful number, since it uses less digits than its factorization.

649179440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12779 (or 12766 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 44.

The square root of 649179440 is about 25478.9999803760. Note that the first 4 decimals coincide. The cubic root of 649179440 is about 865.8744384305.

The spelling of 649179440 in words is "six hundred forty-nine million, one hundred seventy-nine thousand, four hundred forty".