20724799 has 4 divisors (see below), whose sum is σ = 20840760. Its totient is φ = 20608840.

The previous prime is 20724797. The next prime is 20724827. The reversal of 20724799 is 99742702.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99742702 = 2 ⋅49871351.

It is a cyclic number.

It is not a de Polignac number, because 20724799 - 2¹ = 20724797 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20724793) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57712 + ... + 58069.

It is an arithmetic number, because the mean of its divisors is an integer number (5210190).

Almost surely, 2^20724799 is an apocalyptic number.

20724799 is a deficient number, since it is larger than the sum of its proper divisors (115961).

20724799 is a wasteful number, since it uses less digits than its factorization.

20724799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115960.

The product of its (nonzero) digits is 63504, while the sum is 40.

The square root of 20724799 is about 4552.4497800635. The cubic root of 20724799 is about 274.6819419257.

The spelling of 20724799 in words is "twenty million, seven hundred twenty-four thousand, seven hundred ninety-nine".