61666573 has 2 divisors, whose sum is σ = 61666574. Its totient is φ = 61666572.

The previous prime is 61666559. The next prime is 61666589. The reversal of 61666573 is 37566616.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61418569 + 248004 = 7837^2 + 498^2 .

It is a cyclic number.

It is not a de Polignac number, because 61666573 - 2¹³ = 61658381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61666523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30833286 + 30833287.

It is an arithmetic number, because the mean of its divisors is an integer number (30833287).

Almost surely, 2^61666573 is an apocalyptic number.

It is an amenable number.

61666573 is a deficient number, since it is larger than the sum of its proper divisors (1).

61666573 is an equidigital number, since it uses as much as digits as its factorization.

61666573 is an odious number, because the sum of its binary digits is odd.

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

The square root of 61666573 is about 7852.8066956980. The cubic root of 61666573 is about 395.0783864090.

The spelling of 61666573 in words is "sixty-one million, six hundred sixty-six thousand, five hundred seventy-three".