66666688888831 has 2 divisors, whose sum is σ = 66666688888832. Its totient is φ = 66666688888830.

The previous prime is 66666688888747. The next prime is 66666688888873. The reversal of 66666688888831 is 13888888666666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66666688888831 - 2⁴³ = 57870595866623 is a prime.

It is a super-2 number, since 2×66666688888831² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66666688888231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33333344444415 + 33333344444416.

It is an arithmetic number, because the mean of its divisors is an integer number (33333344444416).

Almost surely, 2^{66666688888831} is an apocalyptic number.

66666688888831 is a deficient number, since it is larger than the sum of its proper divisors (1).

66666688888831 is an equidigital number, since it uses as much as digits as its factorization.

66666688888831 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36691771392, while the sum is 88.

The spelling of 66666688888831 in words is "sixty-six trillion, six hundred sixty-six billion, six hundred eighty-eight million, eight hundred eighty-eight thousand, eight hundred thirty-one".