66623429 has 2 divisors, whose sum is σ = 66623430. Its totient is φ = 66623428.

The previous prime is 66623363. The next prime is 66623441. The reversal of 66623429 is 92432666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59706529 + 6916900 = 7727^2 + 2630^2 .

It is a cyclic number.

It is not a de Polignac number, because 66623429 - 2²⁰ = 65574853 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is equal to p_3930896 and since 66623429 and 3930896 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 66623392 and 66623401.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66620429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33311714 + 33311715.

It is an arithmetic number, because the mean of its divisors is an integer number (33311715).

Almost surely, 2^66623429 is an apocalyptic number.

It is an amenable number.

66623429 is a deficient number, since it is larger than the sum of its proper divisors (1).

66623429 is an equidigital number, since it uses as much as digits as its factorization.

66623429 is an evil number, because the sum of its binary digits is even.

The product of its digits is 93312, while the sum is 38.

The square root of 66623429 is about 8162.3176243025. The cubic root of 66623429 is about 405.3924540061.

The spelling of 66623429 in words is "sixty-six million, six hundred twenty-three thousand, four hundred twenty-nine".