847959921 has 24 divisors (see below), whose sum is σ = 1273286560. Its totient is φ = 563931072.

The previous prime is 847959919. The next prime is 847959967. The reversal of 847959921 is 129959748.

847959921 is a `hidden beast` number, since 8 + 47 + 9 + 599 + 2 + 1 = 666.

It is not a de Polignac number, because 847959921 - 2¹ = 847959919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (847959901) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 101190 + ... + 109248.

Almost surely, 2^847959921 is an apocalyptic number.

847959921 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

It is an amenable number.

847959921 is a deficient number, since it is larger than the sum of its proper divisors (425326639).

847959921 is an equidigital number, since it uses as much as digits as its factorization.

847959921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8507 (or 8495 counting only the distinct ones).

The product of its digits is 1632960, while the sum is 54.

The square root of 847959921 is about 29119.7513897355. The cubic root of 847959921 is about 946.5097861411.

The spelling of 847959921 in words is "eight hundred forty-seven million, nine hundred fifty-nine thousand, nine hundred twenty-one".