66836261 has 2 divisors, whose sum is σ = 66836262. Its totient is φ = 66836260.

The previous prime is 66836249. The next prime is 66836269. The reversal of 66836261 is 16263866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47748100 + 19088161 = 6910^2 + 4369^2 .

It is a cyclic number.

It is not a de Polignac number, because 66836261 - 2¹⁸ = 66574117 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66836269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33418130 + 33418131.

It is an arithmetic number, because the mean of its divisors is an integer number (33418131).

Almost surely, 2^66836261 is an apocalyptic number.

It is an amenable number.

66836261 is a deficient number, since it is larger than the sum of its proper divisors (1).

66836261 is an equidigital number, since it uses as much as digits as its factorization.

66836261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62208, while the sum is 38.

The square root of 66836261 is about 8175.3447022129. The cubic root of 66836261 is about 405.8236775509.

The spelling of 66836261 in words is "sixty-six million, eight hundred thirty-six thousand, two hundred sixty-one".