861921693 has 12 divisors (see below), whose sum is σ = 1248203580. Its totient is φ = 573134976.

The previous prime is 861921677. The next prime is 861921761. The reversal of 861921693 is 396129168.

It is a happy number.

861921693 is a `hidden beast` number, since 8 + 619 + 21 + 6 + 9 + 3 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 379548324 + 482373369 = 19482^2 + 21963^2 .

It is not a de Polignac number, because 861921693 - 2⁴ = 861921677 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861921653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 119596 + ... + 126597.

It is an arithmetic number, because the mean of its divisors is an integer number (104016965).

Almost surely, 2^861921693 is an apocalyptic number.

It is an amenable number.

861921693 is a deficient number, since it is larger than the sum of its proper divisors (386281887).

861921693 is a wasteful number, since it uses less digits than its factorization.

861921693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246588 (or 246585 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 861921693 is about 29358.5029080163. The cubic root of 861921693 is about 951.6763359181.

The spelling of 861921693 in words is "eight hundred sixty-one million, nine hundred twenty-one thousand, six hundred ninety-three".