866080981 has 2 divisors, whose sum is σ = 866080982. Its totient is φ = 866080980.

The previous prime is 866080967. The next prime is 866081011. The reversal of 866080981 is 189080668.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 676468081 + 189612900 = 26009^2 + 13770^2 .

It is a cyclic number.

It is not a de Polignac number, because 866080981 - 2⁹ = 866080469 is a prime.

It is a super-2 number, since 2×866080981² = 1500192531299844722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866080951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433040490 + 433040491.

It is an arithmetic number, because the mean of its divisors is an integer number (433040491).

Almost surely, 2^866080981 is an apocalyptic number.

It is an amenable number.

866080981 is a deficient number, since it is larger than the sum of its proper divisors (1).

866080981 is an equidigital number, since it uses as much as digits as its factorization.

866080981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 165888, while the sum is 46.

The square root of 866080981 is about 29429.2538301602. The cubic root of 866080981 is about 953.2046827744.

The spelling of 866080981 in words is "eight hundred sixty-six million, eighty thousand, nine hundred eighty-one".