1646664360631 has 4 divisors (see below), whose sum is σ = 1662967968264. Its totient is φ = 1630360753000.

The previous prime is 1646664360629. The next prime is 1646664360659. The reversal of 1646664360631 is 1360634666461.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1646664360631 - 2¹ = 1646664360629 is a prime.

It is a super-3 number, since 3×1646664360631³ (a number of 38 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1646664360431) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 8151803665 + ... + 8151803866.

It is an arithmetic number, because the mean of its divisors is an integer number (415741992066).

Almost surely, 2^{1646664360631} is an apocalyptic number.

1646664360631 is a deficient number, since it is larger than the sum of its proper divisors (16303607633).

1646664360631 is a wasteful number, since it uses less digits than its factorization.

1646664360631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16303607632.

The product of its (nonzero) digits is 6718464, while the sum is 52.

The spelling of 1646664360631 in words is "one trillion, six hundred forty-six billion, six hundred sixty-four million, three hundred sixty thousand, six hundred thirty-one".