20649573 has 40 divisors (see below), whose sum is σ = 35777280. Its totient is φ = 11625120.

The previous prime is 20649571. The next prime is 20649581. The reversal of 20649573 is 37594602.

20649573 is a `hidden beast` number, since 2 + 0 + 649 + 5 + 7 + 3 = 666.

It is not a de Polignac number, because 20649573 - 2¹ = 20649571 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20649571) 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 39 ways as a sum of consecutive naturals, for example, 44563 + ... + 45023.

It is an arithmetic number, because the mean of its divisors is an integer number (894432).

Almost surely, 2^20649573 is an apocalyptic number.

It is an amenable number.

20649573 is a deficient number, since it is larger than the sum of its proper divisors (15127707).

20649573 is an equidigital number, since it uses as much as digits as its factorization.

20649573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 559 (or 550 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 36.

The square root of 20649573 is about 4544.1801240708. The cubic root of 20649573 is about 274.3491960346.

The spelling of 20649573 in words is "twenty million, six hundred forty-nine thousand, five hundred seventy-three".