66816031 has 2 divisors, whose sum is σ = 66816032. Its totient is φ = 66816030.

The previous prime is 66816011. The next prime is 66816037. The reversal of 66816031 is 13061866.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66816031 - 2¹¹ = 66813983 is a prime.

It is a super-2 number, since 2×66816031² = 8928763997185922, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 66815984 and 66816002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66816037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33408015 + 33408016.

It is an arithmetic number, because the mean of its divisors is an integer number (33408016).

Almost surely, 2^66816031 is an apocalyptic number.

66816031 is a deficient number, since it is larger than the sum of its proper divisors (1).

66816031 is an equidigital number, since it uses as much as digits as its factorization.

66816031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 66816031 is about 8174.1073518764. The cubic root of 66816031 is about 405.7827285145.

Adding to 66816031 its reverse (13061866), we get a palindrome (79877897).

The spelling of 66816031 in words is "sixty-six million, eight hundred sixteen thousand, thirty-one".