866781901 has 4 divisors (see below), whose sum is σ = 867497692. Its totient is φ = 866066112.

The previous prime is 866781871. The next prime is 866781911. The reversal of 866781901 is 109187668.

866781901 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 240281001 + 626500900 = 15501^2 + 25030^2 .

It is a cyclic number.

It is not a de Polignac number, because 866781901 - 2¹⁵ = 866749133 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866781911) 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, 356076 + ... + 358501.

It is an arithmetic number, because the mean of its divisors is an integer number (216874423).

Almost surely, 2^866781901 is an apocalyptic number.

It is an amenable number.

866781901 is a deficient number, since it is larger than the sum of its proper divisors (715791).

866781901 is a wasteful number, since it uses less digits than its factorization.

866781901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 715790.

The product of its (nonzero) digits is 145152, while the sum is 46.

The square root of 866781901 is about 29441.1599805442. The cubic root of 866781901 is about 953.4617565297.

The spelling of 866781901 in words is "eight hundred sixty-six million, seven hundred eighty-one thousand, nine hundred one".