66635256640457 has 2 divisors, whose sum is σ = 66635256640458. Its totient is φ = 66635256640456.

The previous prime is 66635256640427. The next prime is 66635256640471. The reversal of 66635256640457 is 75404665253666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45246999574921 + 21388257065536 = 6726589^2 + 4624744^2 .

It is a cyclic number.

It is not a de Polignac number, because 66635256640457 - 2²⁸ = 66634988205001 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66635256640393 and 66635256640402.

It is not a weakly prime, because it can be changed into another prime (66635256640417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33317628320228 + 33317628320229.

It is an arithmetic number, because the mean of its divisors is an integer number (33317628320229).

Almost surely, 2^{66635256640457} is an apocalyptic number.

It is an amenable number.

66635256640457 is a deficient number, since it is larger than the sum of its proper divisors (1).

66635256640457 is an equidigital number, since it uses as much as digits as its factorization.

66635256640457 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 653184000, while the sum is 65.

The spelling of 66635256640457 in words is "sixty-six trillion, six hundred thirty-five billion, two hundred fifty-six million, six hundred forty thousand, four hundred fifty-seven".