646838626838646 has 192 divisors, whose sum is σ = 1512293847353856. Its totient is φ = 183891477918720.

The previous prime is 646838626838609. The next prime is 646838626838659.

646838626838646 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×646838626838646² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

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, 2728317966 + ... + 2728555038.

It is an arithmetic number, because the mean of its divisors is an integer number (7876530454968).

Almost surely, 2^{646838626838646} is an apocalyptic number.

646838626838646 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 646838626838646, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (756146923676928).

646838626838646 is an abundant number, since it is smaller than the sum of its proper divisors (865455220515210).

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

646838626838646 is a wasteful number, since it uses less digits than its factorization.

646838626838646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240259 (or 240248 counting only the distinct ones).

The product of its digits is 55037657088, while the sum is 84.

The spelling of 646838626838646 in words is "six hundred forty-six trillion, eight hundred thirty-eight billion, six hundred twenty-six million, eight hundred thirty-eight thousand, six hundred forty-six".