646616880 has 480 divisors, whose sum is σ = 2729825280. Its totient is φ = 133539840.

The previous prime is 646616833. The next prime is 646616909. The reversal of 646616880 is 88616646.

It is a super-2 number, since 2×646616880² = 836226779001868800, which contains 22 as substring.

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

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 95 ways as a sum of consecutive naturals, for example, 4651851 + ... + 4651989.

It is an arithmetic number, because the mean of its divisors is an integer number (5687136).

Almost surely, 2^646616880 is an apocalyptic number.

646616880 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 646616880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1364912640).

646616880 is an abundant number, since it is smaller than the sum of its proper divisors (2083208400).

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

646616880 is a wasteful number, since it uses less digits than its factorization.

646616880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249 (or 240 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 45.

The square root of 646616880 is about 25428.6625680550. The cubic root of 646616880 is about 864.7336233026.

The spelling of 646616880 in words is "six hundred forty-six million, six hundred sixteen thousand, eight hundred eighty".