20728754 has 4 divisors (see below), whose sum is σ = 31093134. Its totient is φ = 10364376.

The previous prime is 20728733. The next prime is 20728759. The reversal of 20728754 is 45782702.

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., 13890529 + 6838225 = 3727^2 + 2615^2 .

It is not an unprimeable number, because it can be changed into a prime (20728759) 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 as a sum of consecutive naturals, namely, 5182187 + ... + 5182190.

Almost surely, 2^20728754 is an apocalyptic number.

20728754 is a deficient number, since it is larger than the sum of its proper divisors (10364380).

20728754 is a wasteful number, since it uses less digits than its factorization.

20728754 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10364379.

The product of its (nonzero) digits is 31360, while the sum is 35.

The square root of 20728754 is about 4552.8841408496. The cubic root of 20728754 is about 274.6994137153.

The spelling of 20728754 in words is "twenty million, seven hundred twenty-eight thousand, seven hundred fifty-four".