891861845985 has 48 divisors (see below), whose sum is σ = 1686512475648. Its totient is φ = 432396633600.

The previous prime is 891861845969. The next prime is 891861846077. The reversal of 891861845985 is 589548168198.

891861845985 is a `hidden beast` number, since 8 + 9 + 1 + 86 + 18 + 459 + 85 = 666.

It is not a de Polignac number, because 891861845985 - 2⁴ = 891861845969 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 15709200 + ... + 15765870.

It is an arithmetic number, because the mean of its divisors is an integer number (35135676576).

Almost surely, 2^891861845985 is an apocalyptic number.

It is an amenable number.

891861845985 is a deficient number, since it is larger than the sum of its proper divisors (794650629663).

891861845985 is a wasteful number, since it uses less digits than its factorization.

891861845985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88486 (or 88483 counting only the distinct ones).

The product of its digits is 199065600, while the sum is 72.

The spelling of 891861845985 in words is "eight hundred ninety-one billion, eight hundred sixty-one million, eight hundred forty-five thousand, nine hundred eighty-five".