4891791021 has 48 divisors (see below), whose sum is σ = 7736420160. Its totient is φ = 2735416320.

The previous prime is 4891791013. The next prime is 4891791031. The reversal of 4891791021 is 1201971984.

It is not a de Polignac number, because 4891791021 - 2³ = 4891791013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4891791001) 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 47 ways as a sum of consecutive naturals, for example, 240166 + ... + 259736.

It is an arithmetic number, because the mean of its divisors is an integer number (161175420).

Almost surely, 2^4891791021 is an apocalyptic number.

It is an amenable number.

4891791021 is a deficient number, since it is larger than the sum of its proper divisors (2844629139).

4891791021 is a wasteful number, since it uses less digits than its factorization.

4891791021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19646 (or 19633 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 42.

The square root of 4891791021 is about 69941.3398570545. The cubic root of 4891791021 is about 1697.5502224349.

The spelling of 4891791021 in words is "four billion, eight hundred ninety-one million, seven hundred ninety-one thousand, twenty-one".