66563531 has 2 divisors, whose sum is σ = 66563532. Its totient is φ = 66563530.

The previous prime is 66563521. The next prime is 66563557. The reversal of 66563531 is 13536566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66563531 - 2⁶ = 66563467 is a prime.

It is a super-2 number, since 2×66563531² = 8861407318375922, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 66563491 and 66563500.

It is not a weakly prime, because it can be changed into another prime (66563521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33281765 + 33281766.

It is an arithmetic number, because the mean of its divisors is an integer number (33281766).

Almost surely, 2^66563531 is an apocalyptic number.

66563531 is a deficient number, since it is larger than the sum of its proper divisors (1).

66563531 is an equidigital number, since it uses as much as digits as its factorization.

66563531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48600, while the sum is 35.

The square root of 66563531 is about 8158.6476207764. The cubic root of 66563531 is about 405.2709277993.

The spelling of 66563531 in words is "sixty-six million, five hundred sixty-three thousand, five hundred thirty-one".