646579634220 has 288 divisors, whose sum is σ = 2231727930432. Its totient is φ = 156154272768.

The previous prime is 646579634177. The next prime is 646579634237. The reversal of 646579634220 is 22436975646.

646579634220 is a `hidden beast` number, since 6 + 4 + 6 + 579 + 6 + 3 + 42 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3251994 + ... + 3445086.

It is an arithmetic number, because the mean of its divisors is an integer number (7749055314).

Almost surely, 2^646579634220 is an apocalyptic number.

646579634220 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 646579634220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1115863965216).

646579634220 is an abundant number, since it is smaller than the sum of its proper divisors (1585148296212).

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

646579634220 is a wasteful number, since it uses less digits than its factorization.

646579634220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193183 (or 193169 counting only the distinct ones).

The product of its (nonzero) digits is 13063680, while the sum is 54.

The spelling of 646579634220 in words is "six hundred forty-six billion, five hundred seventy-nine million, six hundred thirty-four thousand, two hundred twenty".