840031412921 has 4 divisors (see below), whose sum is σ = 851862841344. Its totient is φ = 828199984500.

The previous prime is 840031412893. The next prime is 840031412939. The reversal of 840031412921 is 129214130048.

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 840031412921 - 2²⁶ = 839964304057 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (840031412971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5915714105 + ... + 5915714246.

It is an arithmetic number, because the mean of its divisors is an integer number (212965710336).

Almost surely, 2^840031412921 is an apocalyptic number.

It is an amenable number.

840031412921 is a deficient number, since it is larger than the sum of its proper divisors (11831428423).

840031412921 is a wasteful number, since it uses less digits than its factorization.

840031412921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11831428422.

The product of its (nonzero) digits is 13824, while the sum is 35.

Adding to 840031412921 its reverse (129214130048), we get a palindrome (969245542969).

The spelling of 840031412921 in words is "eight hundred forty billion, thirty-one million, four hundred twelve thousand, nine hundred twenty-one".