815985961 has 8 divisors (see below), whose sum is σ = 933094400. Its totient is φ = 699012288.

The previous prime is 815985917. The next prime is 815985979. The reversal of 815985961 is 169589518.

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 815985961 - 2⁹ = 815985449 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 815985899 and 815985908.

It is not an unprimeable number, because it can be changed into a prime (815985361) 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, 20361 + ... + 45238.

It is an arithmetic number, because the mean of its divisors is an integer number (116636800).

Almost surely, 2^815985961 is an apocalyptic number.

It is an amenable number.

815985961 is a deficient number, since it is larger than the sum of its proper divisors (117108439).

815985961 is a wasteful number, since it uses less digits than its factorization.

815985961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67383.

The product of its digits is 777600, while the sum is 52.

The square root of 815985961 is about 28565.4679814632. The cubic root of 815985961 is about 934.4603865861.

The spelling of 815985961 in words is "eight hundred fifteen million, nine hundred eighty-five thousand, nine hundred sixty-one".