20905224605 has 6 divisors (see below), whose sum is σ = 25086657498. Its totient is φ = 16723921040.

The previous prime is 20905224589. The next prime is 20905224623. The reversal of 20905224605 is 50642250902.

It can be written as a sum of positive squares in 3 ways, for example, as 2414936164 + 18490288441 = 49142^2 + 135979^2 .

It is not a de Polignac number, because 20905224605 - 2⁴ = 20905224589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 290975 + ... + 355635.

It is an arithmetic number, because the mean of its divisors is an integer number (4181109583).

Almost surely, 2^20905224605 is an apocalyptic number.

It is an amenable number.

20905224605 is a deficient number, since it is larger than the sum of its proper divisors (4181432893).

20905224605 is an frugal number, since it uses more digits than its factorization.

20905224605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129327 (or 64666 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 35.

The spelling of 20905224605 in words is "twenty billion, nine hundred five million, two hundred twenty-four thousand, six hundred five".