861978859 has 8 divisors (see below), whose sum is σ = 985318880. Its totient is φ = 738688896.

The previous prime is 861978853. The next prime is 861978877. The reversal of 861978859 is 958879168.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 861978859 - 2⁹ = 861978347 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 861978797 and 861978806.

It is not an unprimeable number, because it can be changed into a prime (861978853) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37987 + ... + 56275.

It is an arithmetic number, because the mean of its divisors is an integer number (123164860).

Almost surely, 2^861978859 is an apocalyptic number.

861978859 is a deficient number, since it is larger than the sum of its proper divisors (123340021).

861978859 is a wasteful number, since it uses less digits than its factorization.

861978859 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25029.

The product of its digits is 8709120, while the sum is 61.

The square root of 861978859 is about 29359.4764769401. The cubic root of 861978859 is about 951.6973750787.

It can be divided in two parts, 8619 and 78859, that added together give a palindrome (87478).

The spelling of 861978859 in words is "eight hundred sixty-one million, nine hundred seventy-eight thousand, eight hundred fifty-nine".