1646166261623 has 6 divisors (see below), whose sum is σ = 1782535064544. Its totient is φ = 1519538087496.

The previous prime is 1646166261589. The next prime is 1646166261643. The reversal of 1646166261623 is 3261626616461.

It is a de Polignac number, because none of the positive numbers 2^k-1646166261623 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1646166261643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4870314215 + ... + 4870314552.

It is an arithmetic number, because the mean of its divisors is an integer number (297089177424).

Almost surely, 2^{1646166261623} is an apocalyptic number.

1646166261623 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1646166261623 is a deficient number, since it is larger than the sum of its proper divisors (136368802921).

1646166261623 is an equidigital number, since it uses as much as digits as its factorization.

1646166261623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9740628793 (or 9740628780 counting only the distinct ones).

The product of its digits is 2239488, while the sum is 50.

The spelling of 1646166261623 in words is "one trillion, six hundred forty-six billion, one hundred sixty-six million, two hundred sixty-one thousand, six hundred twenty-three".