861822811 has 4 divisors (see below), whose sum is σ = 899293392. Its totient is φ = 824352232.

The previous prime is 861822791. The next prime is 861822839. The reversal of 861822811 is 118228168.

It is a happy number.

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 861822811 - 2⁷ = 861822683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (861828811) 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, 18735256 + ... + 18735301.

It is an arithmetic number, because the mean of its divisors is an integer number (224823348).

Almost surely, 2^861822811 is an apocalyptic number.

861822811 is a deficient number, since it is larger than the sum of its proper divisors (37470581).

861822811 is a wasteful number, since it uses less digits than its factorization.

861822811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37470580.

The product of its digits is 12288, while the sum is 37.

The square root of 861822811 is about 29356.8188160775. The cubic root of 861822811 is about 951.6399415608.

The spelling of 861822811 in words is "eight hundred sixty-one million, eight hundred twenty-two thousand, eight hundred eleven".