20539847 has 12 divisors (see below), whose sum is σ = 21675960. Its totient is φ = 19443456.

The previous prime is 20539829. The next prime is 20539867. The reversal of 20539847 is 74893502.

It is not a de Polignac number, because 20539847 - 2¹⁰ = 20538823 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20539847.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20539807) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 211703 + ... + 211799.

It is an arithmetic number, because the mean of its divisors is an integer number (1806330).

Almost surely, 2^20539847 is an apocalyptic number.

20539847 is a deficient number, since it is larger than the sum of its proper divisors (1136113).

20539847 is an frugal number, since it uses more digits than its factorization.

20539847 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290 (or 193 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 38.

The square root of 20539847 is about 4532.0907978548. The cubic root of 20539847 is about 273.8623947194.

The spelling of 20539847 in words is "twenty million, five hundred thirty-nine thousand, eight hundred forty-seven".