646432621443655 has 32 divisors (see below), whose sum is σ = 829813826185344. Its totient is φ = 481715532988416.

The previous prime is 646432621443611. The next prime is 646432621443671. The reversal of 646432621443655 is 556344126234646.

It is not a de Polignac number, because 646432621443655 - 2¹³ = 646432621435463 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 646432621443593 and 646432621443602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6983994 + ... + 36628423.

It is an arithmetic number, because the mean of its divisors is an integer number (25931682068292).

Almost surely, 2^{646432621443655} is an apocalyptic number.

646432621443655 is a deficient number, since it is larger than the sum of its proper divisors (183381204741689).

646432621443655 is a wasteful number, since it uses less digits than its factorization.

646432621443655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43614235.

The product of its digits is 298598400, while the sum is 61.

The spelling of 646432621443655 in words is "six hundred forty-six trillion, four hundred thirty-two billion, six hundred twenty-one million, four hundred forty-three thousand, six hundred fifty-five".