861972386817 has 4 divisors (see below), whose sum is σ = 1149296515760. Its totient is φ = 574648257876.

The previous prime is 861972386797. The next prime is 861972386819. The reversal of 861972386817 is 718683279168.

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 not a de Polignac number, because 861972386817 - 2¹² = 861972382721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (861972386819) 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, 143662064467 + ... + 143662064472.

It is an arithmetic number, because the mean of its divisors is an integer number (287324128940).

Almost surely, 2^861972386817 is an apocalyptic number.

It is an amenable number.

861972386817 is a deficient number, since it is larger than the sum of its proper divisors (287324128943).

861972386817 is a wasteful number, since it uses less digits than its factorization.

861972386817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287324128942.

The product of its digits is 48771072, while the sum is 66.

The spelling of 861972386817 in words is "eight hundred sixty-one billion, nine hundred seventy-two million, three hundred eighty-six thousand, eight hundred seventeen".