20724445 has 32 divisors (see below), whose sum is σ = 30640896. Its totient is φ = 13132800.

The previous prime is 20724443. The next prime is 20724463. The reversal of 20724445 is 54442702.

It is a happy number.

It is not a de Polignac number, because 20724445 - 2¹ = 20724443 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20724443) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 36010 + ... + 36580.

It is an arithmetic number, because the mean of its divisors is an integer number (957528).

Almost surely, 2^20724445 is an apocalyptic number.

It is an amenable number.

20724445 is a deficient number, since it is larger than the sum of its proper divisors (9916451).

20724445 is a wasteful number, since it uses less digits than its factorization.

20724445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 661.

The product of its (nonzero) digits is 8960, while the sum is 28.

The square root of 20724445 is about 4552.4108997321. The cubic root of 20724445 is about 274.6803779707.

The spelling of 20724445 in words is "twenty million, seven hundred twenty-four thousand, four hundred forty-five".