861311669 has 4 divisors (see below), whose sum is σ = 861373920. Its totient is φ = 861249420.

The previous prime is 861311653. The next prime is 861311683. The reversal of 861311669 is 966113168.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 861311669 - 2⁴ = 861311653 is a prime.

It is a super-2 number, since 2×861311669² = 1483715582311131122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861311699) 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, 14 + ... + 41504.

It is an arithmetic number, because the mean of its divisors is an integer number (215343480).

Almost surely, 2^861311669 is an apocalyptic number.

It is an amenable number.

861311669 is a deficient number, since it is larger than the sum of its proper divisors (62251).

861311669 is a wasteful number, since it uses less digits than its factorization.

861311669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62250.

The product of its digits is 46656, while the sum is 41.

The square root of 861311669 is about 29348.1118472722. Note that the first 3 decimals coincide. The cubic root of 861311669 is about 951.4517670182.

The spelling of 861311669 in words is "eight hundred sixty-one million, three hundred eleven thousand, six hundred sixty-nine".