20851544 has 32 divisors (see below), whose sum is σ = 45446400. Its totient is φ = 8783520.

The previous prime is 20851541. The next prime is 20851549. The reversal of 20851544 is 44515802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20851541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 149 + ... + 6459.

It is an arithmetic number, because the mean of its divisors is an integer number (1420200).

Almost surely, 2^20851544 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 20851544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22723200).

20851544 is an abundant number, since it is smaller than the sum of its proper divisors (24594856).

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

20851544 is a wasteful number, since it uses less digits than its factorization.

20851544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6383 (or 6379 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 29.

The square root of 20851544 is about 4566.3490887141. The cubic root of 20851544 is about 275.2407544543.

The spelling of 20851544 in words is "twenty million, eight hundred fifty-one thousand, five hundred forty-four".