20835238280581 has 2 divisors, whose sum is σ = 20835238280582. Its totient is φ = 20835238280580.

The previous prime is 20835238280489. The next prime is 20835238280587. The reversal of 20835238280581 is 18508283253802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19806362788356 + 1028875492225 = 4450434^2 + 1014335^2 .

It is a cyclic number.

It is not a de Polignac number, because 20835238280581 - 2³⁹ = 20285482466693 is a prime.

It is a super-2 number, since 2×20835238280581² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20835238280587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10417619140290 + 10417619140291.

It is an arithmetic number, because the mean of its divisors is an integer number (10417619140291).

Almost surely, 2^{20835238280581} is an apocalyptic number.

It is an amenable number.

20835238280581 is a deficient number, since it is larger than the sum of its proper divisors (1).

20835238280581 is an equidigital number, since it uses as much as digits as its factorization.

20835238280581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7372800, while the sum is 55.

The spelling of 20835238280581 in words is "twenty trillion, eight hundred thirty-five billion, two hundred thirty-eight million, two hundred eighty thousand, five hundred eighty-one".