646642208460 has 96 divisors (see below), whose sum is σ = 1827470356992. Its totient is φ = 170832471040.

The previous prime is 646642208437. The next prime is 646642208477. The reversal of 646642208460 is 64802246646.

It is a super-2 number, since 2×646642208460² (a number of 24 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15349225 + ... + 15391295.

It is an arithmetic number, because the mean of its divisors is an integer number (19036149552).

Almost surely, 2^646642208460 is an apocalyptic number.

646642208460 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 646642208460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (913735178496).

646642208460 is an abundant number, since it is smaller than the sum of its proper divisors (1180828148532).

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

646642208460 is a wasteful number, since it uses less digits than its factorization.

646642208460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44463 (or 44461 counting only the distinct ones).

The product of its (nonzero) digits is 2654208, while the sum is 48.

The spelling of 646642208460 in words is "six hundred forty-six billion, six hundred forty-two million, two hundred eight thousand, four hundred sixty".