861530143 has 4 divisors (see below), whose sum is σ = 866815768. Its totient is φ = 856244520.

The previous prime is 861530093. The next prime is 861530147. The reversal of 861530143 is 341035168.

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 861530143 - 2¹³ = 861521951 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861530147) 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, 2642568 + ... + 2642893.

It is an arithmetic number, because the mean of its divisors is an integer number (216703942).

Almost surely, 2^861530143 is an apocalyptic number.

861530143 is a deficient number, since it is larger than the sum of its proper divisors (5285625).

861530143 is a wasteful number, since it uses less digits than its factorization.

861530143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5285624.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 861530143 is about 29351.8337246585. The cubic root of 861530143 is about 951.5322063094.

The spelling of 861530143 in words is "eight hundred sixty-one million, five hundred thirty thousand, one hundred forty-three".