646361856 has 360 divisors, whose sum is σ = 2269445024. Its totient is φ = 179159040.

The previous prime is 646361839. The next prime is 646361861. The reversal of 646361856 is 658163646.

646361856 is a `hidden beast` number, since 6 + 4 + 636 + 1 + 8 + 5 + 6 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 8854236 + ... + 8854308.

Almost surely, 2^646361856 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 646361856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1134722512).

646361856 is an abundant number, since it is smaller than the sum of its proper divisors (1623083168).

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

646361856 is an equidigital number, since it uses as much as digits as its factorization.

646361856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169 (or 146 counting only the distinct ones).

The product of its digits is 622080, while the sum is 45.

The square root of 646361856 is about 25423.6475746499. The cubic root of 646361856 is about 864.6199254635.

The spelling of 646361856 in words is "six hundred forty-six million, three hundred sixty-one thousand, eight hundred fifty-six".