866825320563665 has 8 divisors (see below), whose sum is σ = 1040422414679808. Its totient is φ = 693305569782000.

The previous prime is 866825320563619. The next prime is 866825320563677. The reversal of 866825320563665 is 566365023528668.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 866825320563665 - 2¹⁶ = 866825320498129 is a prime.

It is a super-2 number, since 2×866825320563665² (a number of 31 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19335808961 + ... + 19335853790.

It is an arithmetic number, because the mean of its divisors is an integer number (130052801834976).

Almost surely, 2^{866825320563665} is an apocalyptic number.

It is an amenable number.

866825320563665 is a deficient number, since it is larger than the sum of its proper divisors (173597094116143).

866825320563665 is a wasteful number, since it uses less digits than its factorization.

866825320563665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38671667239.

The product of its (nonzero) digits is 2239488000, while the sum is 71.

The spelling of 866825320563665 in words is "eight hundred sixty-six trillion, eight hundred twenty-five billion, three hundred twenty million, five hundred sixty-three thousand, six hundred sixty-five".