20781995577 has 16 divisors (see below), whose sum is σ = 31674120192. Its totient is φ = 11873057040.

The previous prime is 20781995557. The next prime is 20781995623. The reversal of 20781995577 is 77559918702.

It is not a de Polignac number, because 20781995577 - 2⁶ = 20781995513 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20781995577.

It is not an unprimeable number, because it can be changed into a prime (20781995527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11952 + ... + 204222.

It is an arithmetic number, because the mean of its divisors is an integer number (1979632512).

Almost surely, 2^20781995577 is an apocalyptic number.

It is an amenable number.

20781995577 is a deficient number, since it is larger than the sum of its proper divisors (10892124615).

20781995577 is a wasteful number, since it uses less digits than its factorization.

20781995577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197428.

The product of its (nonzero) digits is 11113200, while the sum is 60.

The spelling of 20781995577 in words is "twenty billion, seven hundred eighty-one million, nine hundred ninety-five thousand, five hundred seventy-seven".