861381043 has 2 divisors, whose sum is σ = 861381044. Its totient is φ = 861381042.

The previous prime is 861381029. The next prime is 861381067. The reversal of 861381043 is 340183168.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-861381043 is a prime.

It is not a weakly prime, because it can be changed into another prime (861381023) 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 as a sum of consecutive naturals, namely, 430690521 + 430690522.

It is an arithmetic number, because the mean of its divisors is an integer number (430690522).

Almost surely, 2^861381043 is an apocalyptic number.

861381043 is a deficient number, since it is larger than the sum of its proper divisors (1).

861381043 is an equidigital number, since it uses as much as digits as its factorization.

861381043 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 861381043 is about 29349.2937393730. The cubic root of 861381043 is about 951.4773110984.

The spelling of 861381043 in words is "eight hundred sixty-one million, three hundred eighty-one thousand, forty-three".