61664579 has 2 divisors, whose sum is σ = 61664580. Its totient is φ = 61664578.

The previous prime is 61664531. The next prime is 61664651. The reversal of 61664579 is 97546616.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61664579 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (61664509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30832289 + 30832290.

It is an arithmetic number, because the mean of its divisors is an integer number (30832290).

Almost surely, 2^61664579 is an apocalyptic number.

61664579 is a deficient number, since it is larger than the sum of its proper divisors (1).

61664579 is an equidigital number, since it uses as much as digits as its factorization.

61664579 is an odious number, because the sum of its binary digits is odd.

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

The square root of 61664579 is about 7852.6797336960. The cubic root of 61664579 is about 395.0741280522.

The spelling of 61664579 in words is "sixty-one million, six hundred sixty-four thousand, five hundred seventy-nine".