866788526215831 has 2 divisors, whose sum is σ = 866788526215832. Its totient is φ = 866788526215830.

The previous prime is 866788526215769. The next prime is 866788526215853. The reversal of 866788526215831 is 138512625887668.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 866788526215831 - 2²¹ = 866788524118679 is a prime.

It is a super-2 number, since 2×866788526215831² (a number of 31 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866788526275831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433394263107915 + 433394263107916.

It is an arithmetic number, because the mean of its divisors is an integer number (433394263107916).

Almost surely, 2^{866788526215831} is an apocalyptic number.

866788526215831 is a deficient number, since it is larger than the sum of its proper divisors (1).

866788526215831 is an equidigital number, since it uses as much as digits as its factorization.

866788526215831 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1857945600, while the sum is 76.

The spelling of 866788526215831 in words is "eight hundred sixty-six trillion, seven hundred eighty-eight billion, five hundred twenty-six million, two hundred fifteen thousand, eight hundred thirty-one".