20539481 has 2 divisors, whose sum is σ = 20539482. Its totient is φ = 20539480.

The previous prime is 20539433. The next prime is 20539489. The reversal of 20539481 is 18493502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19758025 + 781456 = 4445^2 + 884^2 .

It is a cyclic number.

It is not a de Polignac number, because 20539481 - 2¹⁰ = 20538457 is a prime.

It is a super-2 number, since 2×20539481² = 843740559498722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20539489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10269740 + 10269741.

It is an arithmetic number, because the mean of its divisors is an integer number (10269741).

Almost surely, 2^20539481 is an apocalyptic number.

It is an amenable number.

20539481 is a deficient number, since it is larger than the sum of its proper divisors (1).

20539481 is an equidigital number, since it uses as much as digits as its factorization.

20539481 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 20539481 is about 4532.0504189605. The cubic root of 20539481 is about 273.8607680563.

The spelling of 20539481 in words is "twenty million, five hundred thirty-nine thousand, four hundred eighty-one".