646403636461 has 16 divisors (see below), whose sum is σ = 725565115008. Its totient is φ = 570700468800.

The previous prime is 646403636381. The next prime is 646403636507. The reversal of 646403636461 is 164636304646.

It is not a de Polignac number, because 646403636461 - 2¹⁵ = 646403603693 is a prime.

It is a super-2 number, since 2×646403636461² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646403636861) 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 15 ways as a sum of consecutive naturals, for example, 1247665 + ... + 1688038.

It is an arithmetic number, because the mean of its divisors is an integer number (45347819688).

Almost surely, 2^646403636461 is an apocalyptic number.

It is an amenable number.

646403636461 is a deficient number, since it is larger than the sum of its proper divisors (79161478547).

646403636461 is a wasteful number, since it uses less digits than its factorization.

646403636461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2936292.

The product of its (nonzero) digits is 4478976, while the sum is 49.

The spelling of 646403636461 in words is "six hundred forty-six billion, four hundred three million, six hundred thirty-six thousand, four hundred sixty-one".