66691433 has 2 divisors, whose sum is σ = 66691434. Its totient is φ = 66691432.

The previous prime is 66691423. The next prime is 66691439. The reversal of 66691433 is 33419666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54878464 + 11812969 = 7408^2 + 3437^2 .

It is a cyclic number.

It is not a de Polignac number, because 66691433 - 2⁶ = 66691369 is a prime.

It is not a weakly prime, because it can be changed into another prime (66691439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33345716 + 33345717.

It is an arithmetic number, because the mean of its divisors is an integer number (33345717).

Almost surely, 2^66691433 is an apocalyptic number.

It is an amenable number.

66691433 is a deficient number, since it is larger than the sum of its proper divisors (1).

66691433 is an equidigital number, since it uses as much as digits as its factorization.

66691433 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69984, while the sum is 38.

The square root of 66691433 is about 8166.4822904357. The cubic root of 66691433 is about 405.5303381024.

The spelling of 66691433 in words is "sixty-six million, six hundred ninety-one thousand, four hundred thirty-three".