3661664663851 has 2 divisors, whose sum is σ = 3661664663852. Its totient is φ = 3661664663850.

The previous prime is 3661664663849. The next prime is 3661664663857. The reversal of 3661664663851 is 1583664661663.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 3661664663851 - 2¹ = 3661664663849 is a prime.

It is a super-2 number, since 2×3661664663851² (a number of 26 digits) contains 22 as substring.

Together with 3661664663849, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 3661664663851.

It is not a weakly prime, because it can be changed into another prime (3661664663857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1830832331925 + 1830832331926.

It is an arithmetic number, because the mean of its divisors is an integer number (1830832331926).

Almost surely, 2^{3661664663851} is an apocalyptic number.

3661664663851 is a deficient number, since it is larger than the sum of its proper divisors (1).

3661664663851 is an equidigital number, since it uses as much as digits as its factorization.

3661664663851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 67184640, while the sum is 61.

The spelling of 3661664663851 in words is "three trillion, six hundred sixty-one billion, six hundred sixty-four million, six hundred sixty-three thousand, eight hundred fifty-one".