20520817675 has 6 divisors (see below), whose sum is σ = 25445813948. Its totient is φ = 16416654120.

The previous prime is 20520817663. The next prime is 20520817679. The reversal of 20520817675 is 57671802502.

It is a de Polignac number, because none of the positive numbers 2^k-20520817675 is a prime.

It is a super-2 number, since 2×20520817675² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20520817679) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 410416329 + ... + 410416378.

Almost surely, 2^20520817675 is an apocalyptic number.

20520817675 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20520817675 is a deficient number, since it is larger than the sum of its proper divisors (4924996273).

20520817675 is an equidigital number, since it uses as much as digits as its factorization.

20520817675 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820832717 (or 820832712 counting only the distinct ones).

The product of its (nonzero) digits is 235200, while the sum is 43.

The spelling of 20520817675 in words is "twenty billion, five hundred twenty million, eight hundred seventeen thousand, six hundred seventy-five".