1641679813 has 2 divisors, whose sum is σ = 1641679814. Its totient is φ = 1641679812.

The previous prime is 1641679801. The next prime is 1641679841. The reversal of 1641679813 is 3189761461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1561988484 + 79691329 = 39522^2 + 8927^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1641679813 is a prime.

It is a super-2 number, since 2×1641679813² = 5390225216823429938, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1641679883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820839906 + 820839907.

It is an arithmetic number, because the mean of its divisors is an integer number (820839907).

Almost surely, 2^1641679813 is an apocalyptic number.

It is an amenable number.

1641679813 is a deficient number, since it is larger than the sum of its proper divisors (1).

1641679813 is an equidigital number, since it uses as much as digits as its factorization.

1641679813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 217728, while the sum is 46.

The square root of 1641679813 is about 40517.6481671876. The cubic root of 1641679813 is about 1179.6762046079.

The spelling of 1641679813 in words is "one billion, six hundred forty-one million, six hundred seventy-nine thousand, eight hundred thirteen".