866788571145631 has 4 divisors (see below), whose sum is σ = 866790081717472. Its totient is φ = 866787060573792.

The previous prime is 866788571145587. The next prime is 866788571145697. The reversal of 866788571145631 is 136541175887668.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 866788571145631 - 2¹⁷ = 866788571014559 is a prime.

It is a super-2 number, since 2×866788571145631² (a number of 31 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866788571155631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 754424871 + ... + 755572936.

It is an arithmetic number, because the mean of its divisors is an integer number (216697520429368).

Almost surely, 2^{866788571145631} is an apocalyptic number.

866788571145631 is a deficient number, since it is larger than the sum of its proper divisors (1510571841).

866788571145631 is a wasteful number, since it uses less digits than its factorization.

866788571145631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1510571840.

The product of its digits is 1625702400, while the sum is 76.

The spelling of 866788571145631 in words is "eight hundred sixty-six trillion, seven hundred eighty-eight billion, five hundred seventy-one million, one hundred forty-five thousand, six hundred thirty-one".