20445935971 has 4 divisors (see below), whose sum is σ = 20446345512. Its totient is φ = 20445526432.

The previous prime is 20445935953. The next prime is 20445935977. The reversal of 20445935971 is 17953954402.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20445935971 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20445935977) 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, 117481 + ... + 233866.

It is an arithmetic number, because the mean of its divisors is an integer number (5111586378).

Almost surely, 2^20445935971 is an apocalyptic number.

20445935971 is a deficient number, since it is larger than the sum of its proper divisors (409541).

20445935971 is an equidigital number, since it uses as much as digits as its factorization.

20445935971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 409540.

The product of its (nonzero) digits is 1360800, while the sum is 49.

The spelling of 20445935971 in words is "twenty billion, four hundred forty-five million, nine hundred thirty-five thousand, nine hundred seventy-one".