20851407584 has 48 divisors (see below), whose sum is σ = 47012249088. Its totient is φ = 8917921152.

The previous prime is 20851407529. The next prime is 20851407589. The reversal of 20851407584 is 48570415802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20851407589) 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 7 ways as a sum of consecutive naturals, for example, 13517 + ... + 204659.

It is an arithmetic number, because the mean of its divisors is an integer number (979421856).

Almost surely, 2^20851407584 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20851407584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23506124544).

20851407584 is an abundant number, since it is smaller than the sum of its proper divisors (26160841504).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20851407584 is a wasteful number, since it uses less digits than its factorization.

20851407584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191647 (or 191639 counting only the distinct ones).

The product of its (nonzero) digits is 358400, while the sum is 44.

The spelling of 20851407584 in words is "twenty billion, eight hundred fifty-one million, four hundred seven thousand, five hundred eighty-four".