844790929921 has 4 divisors (see below), whose sum is σ = 894484514052. Its totient is φ = 795097345792.

The previous prime is 844790929919. The next prime is 844790929987. The reversal of 844790929921 is 129929097448.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 582877279296 + 261913650625 = 763464^2 + 511775^2 .

It is a cyclic number.

It is not a de Polignac number, because 844790929921 - 2¹ = 844790929919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (844790929991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24846792040 + ... + 24846792073.

It is an arithmetic number, because the mean of its divisors is an integer number (223621128513).

Almost surely, 2^844790929921 is an apocalyptic number.

It is an amenable number.

844790929921 is a deficient number, since it is larger than the sum of its proper divisors (49693584131).

844790929921 is a wasteful number, since it uses less digits than its factorization.

844790929921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49693584130.

The product of its (nonzero) digits is 23514624, while the sum is 64.

The spelling of 844790929921 in words is "eight hundred forty-four billion, seven hundred ninety million, nine hundred twenty-nine thousand, nine hundred twenty-one".