66631963 has 2 divisors, whose sum is σ = 66631964. Its totient is φ = 66631962.

The previous prime is 66631933. The next prime is 66631979. The reversal of 66631963 is 36913666.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66631963 is a prime.

It is not a weakly prime, because it can be changed into another prime (66631913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33315981 + 33315982.

It is an arithmetic number, because the mean of its divisors is an integer number (33315982).

Almost surely, 2^66631963 is an apocalyptic number.

66631963 is a deficient number, since it is larger than the sum of its proper divisors (1).

66631963 is an equidigital number, since it uses as much as digits as its factorization.

66631963 is an evil number, because the sum of its binary digits is even.

The product of its digits is 104976, while the sum is 40.

The square root of 66631963 is about 8162.8403757516. The cubic root of 66631963 is about 405.4097625894.

The spelling of 66631963 in words is "sixty-six million, six hundred thirty-one thousand, nine hundred sixty-three".