20576566081 has 4 divisors (see below), whose sum is σ = 20726760132. Its totient is φ = 20426372032.

The previous prime is 20576566079. The next prime is 20576566121. The reversal of 20576566081 is 18066567502.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16431137856 + 4145428225 = 128184^2 + 64385^2 .

It is a cyclic number.

It is not a de Polignac number, because 20576566081 - 2¹ = 20576566079 is a prime.

It is a super-2 number, since 2×20576566081² (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 (20576536081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75096820 + ... + 75097093.

It is an arithmetic number, because the mean of its divisors is an integer number (5181690033).

Almost surely, 2^20576566081 is an apocalyptic number.

It is an amenable number.

20576566081 is a deficient number, since it is larger than the sum of its proper divisors (150194051).

20576566081 is a wasteful number, since it uses less digits than its factorization.

20576566081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150194050.

The product of its (nonzero) digits is 604800, while the sum is 46.

The spelling of 20576566081 in words is "twenty billion, five hundred seventy-six million, five hundred sixty-six thousand, eighty-one".