66215563 has 2 divisors, whose sum is σ = 66215564. Its totient is φ = 66215562.

The previous prime is 66215549. The next prime is 66215587. The reversal of 66215563 is 36551266.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66215563 - 2⁵ = 66215531 is a prime.

It is not a weakly prime, because it can be changed into another prime (66215503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33107781 + 33107782.

It is an arithmetic number, because the mean of its divisors is an integer number (33107782).

Almost surely, 2^66215563 is an apocalyptic number.

66215563 is a deficient number, since it is larger than the sum of its proper divisors (1).

66215563 is an equidigital number, since it uses as much as digits as its factorization.

66215563 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32400, while the sum is 34.

The square root of 66215563 is about 8137.2945749801. The cubic root of 66215563 is about 404.5634945500.

The spelling of 66215563 in words is "sixty-six million, two hundred fifteen thousand, five hundred sixty-three".