648746640 has 240 divisors, whose sum is σ = 2344492800. Its totient is φ = 160247808.

The previous prime is 648746627. The next prime is 648746647. The reversal of 648746640 is 46647846.

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-2 number, since 2×648746640² = 841744405822579200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (648746647) 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 47 ways as a sum of consecutive naturals, for example, 642456 + ... + 643464.

It is an arithmetic number, because the mean of its divisors is an integer number (9768720).

Almost surely, 2^648746640 is an apocalyptic number.

648746640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 648746640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1172246400).

648746640 is an abundant number, since it is smaller than the sum of its proper divisors (1695746160).

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

648746640 is a wasteful number, since it uses less digits than its factorization.

648746640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1094 (or 1085 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 45.

The square root of 648746640 is about 25470.5052953411. The cubic root of 648746640 is about 865.6819730168.

The spelling of 648746640 in words is "six hundred forty-eight million, seven hundred forty-six thousand, six hundred forty".