20391071641 has 4 divisors (see below), whose sum is σ = 20581642512. Its totient is φ = 20200500772.

The previous prime is 20391071573. The next prime is 20391071663. The reversal of 20391071641 is 14617019302.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 14617019302 = 2 ⋅7308509651.

It is a cyclic number.

It is not a de Polignac number, because 20391071641 - 2¹³ = 20391063449 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20391071597 and 20391071606.

It is not an unprimeable number, because it can be changed into a prime (20391072641) 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, 95285275 + ... + 95285488.

It is an arithmetic number, because the mean of its divisors is an integer number (5145410628).

Almost surely, 2^20391071641 is an apocalyptic number.

It is an amenable number.

20391071641 is a deficient number, since it is larger than the sum of its proper divisors (190570871).

20391071641 is a wasteful number, since it uses less digits than its factorization.

20391071641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190570870.

The product of its (nonzero) digits is 9072, while the sum is 34.

The spelling of 20391071641 in words is "twenty billion, three hundred ninety-one million, seventy-one thousand, six hundred forty-one".