566261981 has 2 divisors, whose sum is σ = 566261982. Its totient is φ = 566261980.

The previous prime is 566261951. The next prime is 566261987. The reversal of 566261981 is 189162665.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 385493956 + 180768025 = 19634^2 + 13445^2 .

It is a cyclic number.

It is not a de Polignac number, because 566261981 - 2²⁶ = 499153117 is a prime.

It is a super-2 number, since 2×566261981² = 641305262252088722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (566261987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 283130990 + 283130991.

It is an arithmetic number, because the mean of its divisors is an integer number (283130991).

Almost surely, 2^566261981 is an apocalyptic number.

It is an amenable number.

566261981 is a deficient number, since it is larger than the sum of its proper divisors (1).

566261981 is an equidigital number, since it uses as much as digits as its factorization.

566261981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 155520, while the sum is 44.

The square root of 566261981 is about 23796.2598111552. The cubic root of 566261981 is about 827.3179896819.

The spelling of 566261981 in words is "five hundred sixty-six million, two hundred sixty-one thousand, nine hundred eighty-one".