20724305 has 12 divisors (see below), whose sum is σ = 28929780. Its totient is φ = 14210784.

The previous prime is 20724287. The next prime is 20724349. The reversal of 20724305 is 50342702.

It can be written as a sum of positive squares in 2 ways, for example, as 12845056 + 7879249 = 3584^2 + 2807^2 .

It is not a de Polignac number, because 20724305 - 2⁸ = 20724049 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 42050 + ... + 42539.

It is an arithmetic number, because the mean of its divisors is an integer number (2410815).

Almost surely, 2^20724305 is an apocalyptic number.

It is an amenable number.

20724305 is a deficient number, since it is larger than the sum of its proper divisors (8205475).

20724305 is an equidigital number, since it uses as much as digits as its factorization.

20724305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84608 (or 84601 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 23.

The square root of 20724305 is about 4552.3955232383. The cubic root of 20724305 is about 274.6797594525.

The spelling of 20724305 in words is "twenty million, seven hundred twenty-four thousand, three hundred five".