66542842391 has 2 divisors, whose sum is σ = 66542842392. Its totient is φ = 66542842390.

The previous prime is 66542842351. The next prime is 66542842423. The reversal of 66542842391 is 19324824566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66542842391 - 2²² = 66538648087 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66542842351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33271421195 + 33271421196.

It is an arithmetic number, because the mean of its divisors is an integer number (33271421196).

Almost surely, 2^66542842391 is an apocalyptic number.

66542842391 is a deficient number, since it is larger than the sum of its proper divisors (1).

66542842391 is an equidigital number, since it uses as much as digits as its factorization.

66542842391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2488320, while the sum is 50.

The spelling of 66542842391 in words is "sixty-six billion, five hundred forty-two million, eight hundred forty-two thousand, three hundred ninety-one".