66479561 has 2 divisors, whose sum is σ = 66479562. Its totient is φ = 66479560.

The previous prime is 66479557. The next prime is 66479563. The reversal of 66479561 is 16597466.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66259600 + 219961 = 8140^2 + 469^2 .

It is a cyclic number.

It is not a de Polignac number, because 66479561 - 2² = 66479557 is a prime.

Together with 66479563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66479563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33239780 + 33239781.

It is an arithmetic number, because the mean of its divisors is an integer number (33239781).

Almost surely, 2^66479561 is an apocalyptic number.

It is an amenable number.

66479561 is a deficient number, since it is larger than the sum of its proper divisors (1).

66479561 is an equidigital number, since it uses as much as digits as its factorization.

66479561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 272160, while the sum is 44.

The square root of 66479561 is about 8153.4999233458. The cubic root of 66479561 is about 405.1004394492.

The spelling of 66479561 in words is "sixty-six million, four hundred seventy-nine thousand, five hundred sixty-one".