840733021 has 4 divisors (see below), whose sum is σ = 846781600. Its totient is φ = 834684444.

The previous prime is 840733009. The next prime is 840733027. The reversal of 840733021 is 120337048.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 840733021 - 2²³ = 832344413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840733027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3024081 + ... + 3024358.

It is an arithmetic number, because the mean of its divisors is an integer number (211695400).

Almost surely, 2^840733021 is an apocalyptic number.

840733021 is the 16741-st hex number.

It is an amenable number.

840733021 is a deficient number, since it is larger than the sum of its proper divisors (6048579).

840733021 is a wasteful number, since it uses less digits than its factorization.

840733021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6048578.

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 840733021 is about 28995.3965484178. The cubic root of 840733021 is about 943.8131741053.

The spelling of 840733021 in words is "eight hundred forty million, seven hundred thirty-three thousand, twenty-one".