20986845 has 48 divisors (see below), whose sum is σ = 38201856. Its totient is φ = 9820800.

The previous prime is 20986841. The next prime is 20986853. The reversal of 20986845 is 54868902.

20986845 = 355² + 356² + ... + 475².

It is not a de Polignac number, because 20986845 - 2² = 20986841 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20986797 and 20986806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20986841) 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 47 ways as a sum of consecutive naturals, for example, 56079 + ... + 56451.

It is an arithmetic number, because the mean of its divisors is an integer number (795872).

Almost surely, 2^20986845 is an apocalyptic number.

It is an amenable number.

20986845 is a deficient number, since it is larger than the sum of its proper divisors (17215011).

20986845 is a wasteful number, since it uses less digits than its factorization.

20986845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434 (or 423 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 42.

The square root of 20986845 is about 4581.1401419297. The cubic root of 20986845 is about 275.8347966403.

The spelling of 20986845 in words is "twenty million, nine hundred eighty-six thousand, eight hundred forty-five".