866719641 has 4 divisors (see below), whose sum is σ = 1155626192. Its totient is φ = 577813092.

The previous prime is 866719631. The next prime is 866719643. The reversal of 866719641 is 146917668.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 866719641 - 2¹⁸ = 866457497 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (866719643) 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, 144453271 + ... + 144453276.

It is an arithmetic number, because the mean of its divisors is an integer number (288906548).

Almost surely, 2^866719641 is an apocalyptic number.

It is an amenable number.

866719641 is a deficient number, since it is larger than the sum of its proper divisors (288906551).

866719641 is a wasteful number, since it uses less digits than its factorization.

866719641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288906550.

The product of its digits is 435456, while the sum is 48.

The square root of 866719641 is about 29440.1025983267. The cubic root of 866719641 is about 953.4389272765.

The spelling of 866719641 in words is "eight hundred sixty-six million, seven hundred nineteen thousand, six hundred forty-one".