66623131 has 2 divisors, whose sum is σ = 66623132. Its totient is φ = 66623130.

The previous prime is 66623113. The next prime is 66623143. The reversal of 66623131 is 13132666.

Together with previous prime (66623113) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66623131 - 2⁵ = 66623099 is a prime.

It is a super-2 number, since 2×66623131² = 8877283168486322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66623131.

It is not a weakly prime, because it can be changed into another prime (66623191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33311565 + 33311566.

It is an arithmetic number, because the mean of its divisors is an integer number (33311566).

Almost surely, 2^66623131 is an apocalyptic number.

66623131 is a deficient number, since it is larger than the sum of its proper divisors (1).

66623131 is an equidigital number, since it uses as much as digits as its factorization.

66623131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3888, while the sum is 28.

The square root of 66623131 is about 8162.2993696629. The cubic root of 66623131 is about 405.3918495785.

Adding to 66623131 its reverse (13132666), we get a palindrome (79755797).

The spelling of 66623131 in words is "sixty-six million, six hundred twenty-three thousand, one hundred thirty-one".