646575575646 has 256 divisors, whose sum is σ = 1790732224512. Its totient is φ = 150194995200.

The previous prime is 646575575641. The next prime is 646575575651.

646575575646 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (646575575641) and next prime (646575575651).

It is a Harshad number since it is a multiple of its sum of digits (66).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646575575641) by changing a digit.

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 127 ways as a sum of consecutive naturals, for example, 53549466 + ... + 53561538.

It is an arithmetic number, because the mean of its divisors is an integer number (6995047752).

Almost surely, 2^646575575646 is an apocalyptic number.

646575575646 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 646575575646, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (895366112256).

646575575646 is an abundant number, since it is smaller than the sum of its proper divisors (1144156648866).

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

646575575646 is a wasteful number, since it uses less digits than its factorization.

646575575646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12387.

The product of its digits is 635040000, while the sum is 66.

It can be divided in two parts, 646575 and 575646, that added together give a palindrome (1222221).

The spelling of 646575575646 in words is "six hundred forty-six billion, five hundred seventy-five million, five hundred seventy-five thousand, six hundred forty-six".