3661664663857 has 2 divisors, whose sum is σ = 3661664663858. Its totient is φ = 3661664663856.

The previous prime is 3661664663851. The next prime is 3661664663897. The reversal of 3661664663857 is 7583664661663.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3277997154576 + 383667509281 = 1810524^2 + 619409^2 .

It is an emirp because it is prime and its reverse (7583664661663) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3661664663857 - 2³ = 3661664663849 is a prime.

It is a super-2 number, since 2×3661664663857² (a number of 26 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 3661664663792 and 3661664663801.

It is not a weakly prime, because it can be changed into another prime (3661664663851) 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 as a sum of consecutive naturals, namely, 1830832331928 + 1830832331929.

It is an arithmetic number, because the mean of its divisors is an integer number (1830832331929).

Almost surely, 2^{3661664663857} is an apocalyptic number.

It is an amenable number.

3661664663857 is a deficient number, since it is larger than the sum of its proper divisors (1).

3661664663857 is an equidigital number, since it uses as much as digits as its factorization.

3661664663857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 470292480, while the sum is 67.

The spelling of 3661664663857 in words is "three trillion, six hundred sixty-one billion, six hundred sixty-four million, six hundred sixty-three thousand, eight hundred fifty-seven".