861134721 has 4 divisors (see below), whose sum is σ = 1148179632. Its totient is φ = 574089812.

The previous prime is 861134713. The next prime is 861134723. The reversal of 861134721 is 127431168.

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 a cyclic number.

It is not a de Polignac number, because 861134721 - 2³ = 861134713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (861134723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 143522451 + ... + 143522456.

It is an arithmetic number, because the mean of its divisors is an integer number (287044908).

Almost surely, 2^861134721 is an apocalyptic number.

It is an amenable number.

861134721 is a deficient number, since it is larger than the sum of its proper divisors (287044911).

861134721 is a wasteful number, since it uses less digits than its factorization.

861134721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287044910.

The product of its digits is 8064, while the sum is 33.

The square root of 861134721 is about 29345.0970521483. The cubic root of 861134721 is about 951.3866070908.

Adding to 861134721 its reverse (127431168), we get a palindrome (988565889).

The spelling of 861134721 in words is "eight hundred sixty-one million, one hundred thirty-four thousand, seven hundred twenty-one".