842808021 has 32 divisors (see below), whose sum is σ = 1283724288. Its totient is φ = 486858240.

The previous prime is 842808011. The next prime is 842808059. The reversal of 842808021 is 120808248.

It is not a de Polignac number, because 842808021 - 2⁵ = 842807989 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (842808011) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 231205 + ... + 234821.

It is an arithmetic number, because the mean of its divisors is an integer number (40116384).

Almost surely, 2^842808021 is an apocalyptic number.

It is an amenable number.

842808021 is a deficient number, since it is larger than the sum of its proper divisors (440916267).

842808021 is a wasteful number, since it uses less digits than its factorization.

842808021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3961.

The product of its (nonzero) digits is 8192, while the sum is 33.

The square root of 842808021 is about 29031.1560396757. The cubic root of 842808021 is about 944.5890063523.

The spelling of 842808021 in words is "eight hundred forty-two million, eight hundred eight thousand, twenty-one".