866786257554642 has 40 divisors (see below), whose sum is σ = 1952003297376000. Its totient is φ = 287476849228536.

The previous prime is 866786257554593. The next prime is 866786257554661. The reversal of 866786257554642 is 246455752687668.

866786257554642 is a `hidden beast` number, since 8 + 6 + 6 + 7 + 8 + 6 + 2 + 57 + 554 + 6 + 4 + 2 = 666.

866786257554642 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 13443516642 + ... + 13443581117.

It is an arithmetic number, because the mean of its divisors is an integer number (48800082434400).

Almost surely, 2^{866786257554642} is an apocalyptic number.

866786257554642 is an abundant number, since it is smaller than the sum of its proper divisors (1085217039821358).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

866786257554642 is a wasteful number, since it uses less digits than its factorization.

866786257554642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26887097972 (or 26887097963 counting only the distinct ones).

The product of its digits is 32514048000, while the sum is 81.

The spelling of 866786257554642 in words is "eight hundred sixty-six trillion, seven hundred eighty-six billion, two hundred fifty-seven million, five hundred fifty-four thousand, six hundred forty-two".