20851124 has 36 divisors (see below), whose sum is σ = 42840672. Its totient is φ = 8698560.

The previous prime is 20851109. The next prime is 20851211. The reversal of 20851124 is 42115802.

It is a self number, because there is not a number n which added to its sum of digits gives 20851124.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 46847 + ... + 47289.

Almost surely, 2^20851124 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 20851124, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21420336).

20851124 is an abundant number, since it is smaller than the sum of its proper divisors (21989548).

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

20851124 is a wasteful number, since it uses less digits than its factorization.

20851124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 536 (or 493 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 20851124 is about 4566.3030998829. The cubic root of 20851124 is about 275.2389064393.

Adding to 20851124 its reverse (42115802), we get a palindrome (62966926).

The spelling of 20851124 in words is "twenty million, eight hundred fifty-one thousand, one hundred twenty-four".