66735661 has 2 divisors, whose sum is σ = 66735662. Its totient is φ = 66735660.

The previous prime is 66735637. The next prime is 66735677. The reversal of 66735661 is 16653766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38316100 + 28419561 = 6190^2 + 5331^2 .

It is a cyclic number.

It is not a de Polignac number, because 66735661 - 2¹⁵ = 66702893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66735631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33367830 + 33367831.

It is an arithmetic number, because the mean of its divisors is an integer number (33367831).

Almost surely, 2^66735661 is an apocalyptic number.

It is an amenable number.

66735661 is a deficient number, since it is larger than the sum of its proper divisors (1).

66735661 is an equidigital number, since it uses as much as digits as its factorization.

66735661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 136080, while the sum is 40.

The square root of 66735661 is about 8169.1897395029. The cubic root of 66735661 is about 405.6199639689.

The spelling of 66735661 in words is "sixty-six million, seven hundred thirty-five thousand, six hundred sixty-one".