20439541 has 2 divisors, whose sum is σ = 20439542. Its totient is φ = 20439540.

The previous prime is 20439493. The next prime is 20439557. The reversal of 20439541 is 14593402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20439441 + 100 = 4521^2 + 10^2 .

It is a cyclic number.

It is not a de Polignac number, because 20439541 - 2¹⁹ = 19915253 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20439641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10219770 + 10219771.

It is an arithmetic number, because the mean of its divisors is an integer number (10219771).

Almost surely, 2^20439541 is an apocalyptic number.

It is an amenable number.

20439541 is a deficient number, since it is larger than the sum of its proper divisors (1).

20439541 is an equidigital number, since it uses as much as digits as its factorization.

20439541 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 20439541 is about 4521.0110594866. The cubic root of 20439541 is about 273.4158662460.

The spelling of 20439541 in words is "twenty million, four hundred thirty-nine thousand, five hundred forty-one".