20969844 has 72 divisors (see below), whose sum is σ = 59945760. Its totient is φ = 5673024.

The previous prime is 20969833. The next prime is 20969869. The reversal of 20969844 is 44896902.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 20969796 and 20969805.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 10234 + ... + 12110.

It is an arithmetic number, because the mean of its divisors is an integer number (832580).

Almost surely, 2^20969844 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 20969844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29972880).

20969844 is an abundant number, since it is smaller than the sum of its proper divisors (38975916).

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

20969844 is a wasteful number, since it uses less digits than its factorization.

20969844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1917 (or 1908 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 42.

The square root of 20969844 is about 4579.2842235441. The cubic root of 20969844 is about 275.7602938708.

The spelling of 20969844 in words is "twenty million, nine hundred sixty-nine thousand, eight hundred forty-four".