20757539 has 4 divisors (see below), whose sum is σ = 22644600. Its totient is φ = 18870480.

The previous prime is 20757511. The next prime is 20757577. The reversal of 20757539 is 93575702.

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

It is a cyclic number.

It is not a de Polignac number, because 20757539 - 2⁸ = 20757283 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20757589) 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 in 3 ways as a sum of consecutive naturals, for example, 943514 + ... + 943535.

It is an arithmetic number, because the mean of its divisors is an integer number (5661150).

Almost surely, 2^20757539 is an apocalyptic number.

20757539 is a deficient number, since it is larger than the sum of its proper divisors (1887061).

20757539 is a wasteful number, since it uses less digits than its factorization.

20757539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1887060.

The product of its (nonzero) digits is 66150, while the sum is 38.

The square root of 20757539 is about 4556.0442271778. The cubic root of 20757539 is about 274.8265087532.

The spelling of 20757539 in words is "twenty million, seven hundred fifty-seven thousand, five hundred thirty-nine".