66814831 has 2 divisors, whose sum is σ = 66814832. Its totient is φ = 66814830.

The previous prime is 66814829. The next prime is 66814837. The reversal of 66814831 is 13841866.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66814831 - 2¹ = 66814829 is a prime.

It is a super-2 number, since 2×66814831² = 8928443283117122, which contains 22 as substring.

Together with 66814829, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66814837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33407415 + 33407416.

It is an arithmetic number, because the mean of its divisors is an integer number (33407416).

Almost surely, 2^66814831 is an apocalyptic number.

66814831 is a deficient number, since it is larger than the sum of its proper divisors (1).

66814831 is an equidigital number, since it uses as much as digits as its factorization.

66814831 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27648, while the sum is 37.

The square root of 66814831 is about 8174.0339490364. The cubic root of 66814831 is about 405.7802992463.

The spelling of 66814831 in words is "sixty-six million, eight hundred fourteen thousand, eight hundred thirty-one".