861731097 has 4 divisors (see below), whose sum is σ = 1148974800. Its totient is φ = 574487396.

The previous prime is 861731089. The next prime is 861731113. The reversal of 861731097 is 790137168.

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 861731097 - 2³ = 861731089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (861731077) 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, 143621847 + ... + 143621852.

It is an arithmetic number, because the mean of its divisors is an integer number (287243700).

Almost surely, 2^861731097 is an apocalyptic number.

It is an amenable number.

861731097 is a deficient number, since it is larger than the sum of its proper divisors (287243703).

861731097 is a wasteful number, since it uses less digits than its factorization.

861731097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287243702.

The product of its (nonzero) digits is 63504, while the sum is 42.

The square root of 861731097 is about 29355.2567183460. The cubic root of 861731097 is about 951.6061829580.

The spelling of 861731097 in words is "eight hundred sixty-one million, seven hundred thirty-one thousand, ninety-seven".