842567921 has 6 divisors (see below), whose sum is σ = 912366630. Its totient is φ = 777754848.

The previous prime is 842567909. The next prime is 842567927. The reversal of 842567921 is 129765248.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 48455521 + 794112400 = 6961^2 + 28180^2 .

It is a de Polignac number, because none of the positive numbers 2^k-842567921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (842567927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2492636 + ... + 2492973.

It is an arithmetic number, because the mean of its divisors is an integer number (152061105).

Almost surely, 2^842567921 is an apocalyptic number.

It is an amenable number.

842567921 is a deficient number, since it is larger than the sum of its proper divisors (69798709).

842567921 is a wasteful number, since it uses less digits than its factorization.

842567921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4985635 (or 4985622 counting only the distinct ones).

The product of its digits is 241920, while the sum is 44.

The square root of 842567921 is about 29027.0205326003. The cubic root of 842567921 is about 944.4992993432.

The spelling of 842567921 in words is "eight hundred forty-two million, five hundred sixty-seven thousand, nine hundred twenty-one".