646120121021646 has 32 divisors (see below), whose sum is σ = 1397016477893760. Its totient is φ = 198523394224416.

The previous prime is 646120121021593. The next prime is 646120121021659.

It is a happy number.

646120121021646 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 646120121021598 and 646120121021607.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76590811456 + ... + 76590819891.

It is an arithmetic number, because the mean of its divisors is an integer number (43656764934180).

Almost surely, 2^{646120121021646} is an apocalyptic number.

646120121021646 is an abundant number, since it is smaller than the sum of its proper divisors (750896356872114).

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

646120121021646 is a wasteful number, since it uses less digits than its factorization.

646120121021646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153181631408.

The product of its (nonzero) digits is 165888, while the sum is 42.

The spelling of 646120121021646 in words is "six hundred forty-six trillion, one hundred twenty billion, one hundred twenty-one million, twenty-one thousand, six hundred forty-six".