66342021257 has 2 divisors, whose sum is σ = 66342021258. Its totient is φ = 66342021256.

The previous prime is 66342021253. The next prime is 66342021283. The reversal of 66342021257 is 75212024366.

66342021257 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54483029056 + 11858992201 = 233416^2 + 108899^2 .

It is a cyclic number.

It is not a de Polignac number, because 66342021257 - 2² = 66342021253 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66342021257.

It is not a weakly prime, because it can be changed into another prime (66342021253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33171010628 + 33171010629.

It is an arithmetic number, because the mean of its divisors is an integer number (33171010629).

Almost surely, 2^66342021257 is an apocalyptic number.

It is an amenable number.

66342021257 is a deficient number, since it is larger than the sum of its proper divisors (1).

66342021257 is an equidigital number, since it uses as much as digits as its factorization.

66342021257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 38.

The spelling of 66342021257 in words is "sixty-six billion, three hundred forty-two million, twenty-one thousand, two hundred fifty-seven".