20815370605 has 8 divisors (see below), whose sum is σ = 26447765112. Its totient is φ = 15672749568.

The previous prime is 20815370581. The next prime is 20815370617. The reversal of 20815370605 is 50607351802.

It can be written as a sum of positive squares in 4 ways, for example, as 3387938436 + 17427432169 = 58206^2 + 132013^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20815370605 - 2²⁵ = 20781816173 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 7 ways as a sum of consecutive naturals, for example, 122443272 + ... + 122443441.

It is an arithmetic number, because the mean of its divisors is an integer number (3305970639).

Almost surely, 2^20815370605 is an apocalyptic number.

It is an amenable number.

20815370605 is a deficient number, since it is larger than the sum of its proper divisors (5632394507).

20815370605 is a wasteful number, since it uses less digits than its factorization.

20815370605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244886735.

The product of its (nonzero) digits is 50400, while the sum is 37.

The spelling of 20815370605 in words is "twenty billion, eight hundred fifteen million, three hundred seventy thousand, six hundred five".