20724754 has 4 divisors (see below), whose sum is σ = 31087134. Its totient is φ = 10362376.

The previous prime is 20724731. The next prime is 20724793. The reversal of 20724754 is 45742702.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 16200625 + 4524129 = 4025^2 + 2127^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5181187 + ... + 5181190.

Almost surely, 2^20724754 is an apocalyptic number.

20724754 is a deficient number, since it is larger than the sum of its proper divisors (10362380).

20724754 is a wasteful number, since it uses less digits than its factorization.

20724754 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10362379.

The product of its (nonzero) digits is 15680, while the sum is 31.

The square root of 20724754 is about 4552.4448376669. Note that the first 3 decimals coincide. The cubic root of 20724754 is about 274.6817431189.

The spelling of 20724754 in words is "twenty million, seven hundred twenty-four thousand, seven hundred fifty-four".