866121539 has 2 divisors, whose sum is σ = 866121540. Its totient is φ = 866121538.

The previous prime is 866121533. The next prime is 866121551. The reversal of 866121539 is 935121668.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 866121539 - 2¹² = 866117443 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 866121496 and 866121505.

It is not a weakly prime, because it can be changed into another prime (866121533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433060769 + 433060770.

It is an arithmetic number, because the mean of its divisors is an integer number (433060770).

Almost surely, 2^866121539 is an apocalyptic number.

866121539 is a deficient number, since it is larger than the sum of its proper divisors (1).

866121539 is an equidigital number, since it uses as much as digits as its factorization.

866121539 is an evil number, because the sum of its binary digits is even.

The product of its digits is 77760, while the sum is 41.

The square root of 866121539 is about 29429.9428983476. The cubic root of 866121539 is about 953.2195618572.

The spelling of 866121539 in words is "eight hundred sixty-six million, one hundred twenty-one thousand, five hundred thirty-nine".