20539147 has 4 divisors (see below), whose sum is σ = 20593720. Its totient is φ = 20484576.

The previous prime is 20539121. The next prime is 20539157. The reversal of 20539147 is 74193502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74193502 = 2 ⋅37096751.

It is a cyclic number.

It is not a de Polignac number, because 20539147 - 2¹⁹ = 20014859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20539117) 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, 26718 + ... + 27475.

It is an arithmetic number, because the mean of its divisors is an integer number (5148430).

Almost surely, 2^20539147 is an apocalyptic number.

20539147 is a deficient number, since it is larger than the sum of its proper divisors (54573).

20539147 is an equidigital number, since it uses as much as digits as its factorization.

20539147 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54572.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 20539147 is about 4532.0135701474. The cubic root of 20539147 is about 273.8592835983.

The spelling of 20539147 in words is "twenty million, five hundred thirty-nine thousand, one hundred forty-seven".