20506221271 has 8 divisors (see below), whose sum is σ = 20804333760. Its totient is φ = 20209878528.

The previous prime is 20506221247. The next prime is 20506221319. The reversal of 20506221271 is 17212260502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20506221271 is a prime.

It is a super-2 number, since 2×20506221271² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20506228271) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 419086 + ... + 465451.

It is an arithmetic number, because the mean of its divisors is an integer number (2600541720).

Almost surely, 2^20506221271 is an apocalyptic number.

20506221271 is a deficient number, since it is larger than the sum of its proper divisors (298112489).

20506221271 is an equidigital number, since it uses as much as digits as its factorization.

20506221271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 884873.

The product of its (nonzero) digits is 3360, while the sum is 28.

Adding to 20506221271 its reverse (17212260502), we get a palindrome (37718481773).

The spelling of 20506221271 in words is "twenty billion, five hundred six million, two hundred twenty-one thousand, two hundred seventy-one".