861221043 has 12 divisors (see below), whose sum is σ = 1252336800. Its totient is φ = 570293136.

The previous prime is 861221021. The next prime is 861221047. The reversal of 861221043 is 340122168.

861221043 is a `hidden beast` number, since 8 + 612 + 2 + 1 + 0 + 43 = 666.

861221043 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-861221043 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 861220998 and 861221016.

It is not an unprimeable number, because it can be changed into a prime (861221047) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 319771 + ... + 322452.

It is an arithmetic number, because the mean of its divisors is an integer number (104361400).

Almost surely, 2^861221043 is an apocalyptic number.

861221043 is a deficient number, since it is larger than the sum of its proper divisors (391115757).

861221043 is a wasteful number, since it uses less digits than its factorization.

861221043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 642378 (or 642375 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 861221043 is about 29346.5678231714. The cubic root of 861221043 is about 951.4183957098.

The spelling of 861221043 in words is "eight hundred sixty-one million, two hundred twenty-one thousand, forty-three".