20520239 has 4 divisors (see below), whose sum is σ = 20534520. Its totient is φ = 20505960.

The previous prime is 20520229. The next prime is 20520257. The reversal of 20520239 is 93202502.

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 20520239 - 2²⁰ = 19471663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20520229) 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, 4709 + ... + 7950.

It is an arithmetic number, because the mean of its divisors is an integer number (5133630).

Almost surely, 2^20520239 is an apocalyptic number.

20520239 is a deficient number, since it is larger than the sum of its proper divisors (14281).

20520239 is a wasteful number, since it uses less digits than its factorization.

20520239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14280.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 20520239 is about 4529.9270413551. The cubic root of 20520239 is about 273.7752210175.

The spelling of 20520239 in words is "twenty million, five hundred twenty thousand, two hundred thirty-nine".