20681441 has 6 divisors (see below), whose sum is σ = 22732626. Its totient is φ = 18801200.

The previous prime is 20681407. The next prime is 20681449. The reversal of 20681441 is 14418602.

It can be written as a sum of positive squares in only one way, i.e., 18309841 + 2371600 = 4279^2 + 1540^2 .

It is a de Polignac number, because none of the positive numbers 2^k-20681441 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20681441.

It is not an unprimeable number, because it can be changed into a prime (20681449) 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 5 ways as a sum of consecutive naturals, for example, 85340 + ... + 85581.

It is an arithmetic number, because the mean of its divisors is an integer number (3788771).

Almost surely, 2^20681441 is an apocalyptic number.

It is an amenable number.

20681441 is a deficient number, since it is larger than the sum of its proper divisors (2051185).

20681441 is a wasteful number, since it uses less digits than its factorization.

20681441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170943 (or 170932 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 20681441 is about 4547.6852353697. The cubic root of 20681441 is about 274.4902557139.

The spelling of 20681441 in words is "twenty million, six hundred eighty-one thousand, four hundred forty-one".