20210021171 has 2 divisors, whose sum is σ = 20210021172. Its totient is φ = 20210021170.

The previous prime is 20210021131. The next prime is 20210021219. The reversal of 20210021171 is 17112001202.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20210021171 is a prime.

It is a super-2 number, since 2×20210021171² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20210021131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105010585 + 10105010586.

It is an arithmetic number, because the mean of its divisors is an integer number (10105010586).

Almost surely, 2^20210021171 is an apocalyptic number.

20210021171 is a deficient number, since it is larger than the sum of its proper divisors (1).

20210021171 is an equidigital number, since it uses as much as digits as its factorization.

20210021171 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56, while the sum is 17.

Adding to 20210021171 its reverse (17112001202), we get a palindrome (37322022373).

The spelling of 20210021171 in words is "twenty billion, two hundred ten million, twenty-one thousand, one hundred seventy-one".