866320381 has 2 divisors, whose sum is σ = 866320382. Its totient is φ = 866320380.

The previous prime is 866320373. The next prime is 866320417. The reversal of 866320381 is 183023668.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 573602500 + 292717881 = 23950^2 + 17109^2 .

It is a cyclic number.

It is not a de Polignac number, because 866320381 - 2³ = 866320373 is a prime.

It is a super-2 number, since 2×866320381² = 1501022005071970322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 866320381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866320321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433160190 + 433160191.

It is an arithmetic number, because the mean of its divisors is an integer number (433160191).

Almost surely, 2^866320381 is an apocalyptic number.

It is an amenable number.

866320381 is a deficient number, since it is larger than the sum of its proper divisors (1).

866320381 is an equidigital number, since it uses as much as digits as its factorization.

866320381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 37.

The square root of 866320381 is about 29433.3209305372. The cubic root of 866320381 is about 953.2925021906.

The spelling of 866320381 in words is "eight hundred sixty-six million, three hundred twenty thousand, three hundred eighty-one".