20651005 has 24 divisors (see below), whose sum is σ = 27733752. Its totient is φ = 14708736.

The previous prime is 20650997. The next prime is 20651021. The reversal of 20651005 is 50015602.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2859481 + 17791524 = 1691^2 + 4218^2 .

It is not a de Polignac number, because 20651005 - 2³ = 20650997 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

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, 30349 + ... + 31021.

It is an arithmetic number, because the mean of its divisors is an integer number (1155573).

Almost surely, 2^20651005 is an apocalyptic number.

It is an amenable number.

20651005 is a deficient number, since it is larger than the sum of its proper divisors (7082747).

20651005 is a wasteful number, since it uses less digits than its factorization.

20651005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 733 (or 714 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 20651005 is about 4544.3376855159. The cubic root of 20651005 is about 274.3555377149.

Adding to 20651005 its reverse (50015602), we get a palindrome (70666607).

The spelling of 20651005 in words is "twenty million, six hundred fifty-one thousand, five".