21101215271 has 2 divisors, whose sum is σ = 21101215272. Its totient is φ = 21101215270.

The previous prime is 21101215241. The next prime is 21101215283. The reversal of 21101215271 is 17251210112.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21101215271 - 2⁶ = 21101215207 is a prime.

It is a super-2 number, since 2×21101215271² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21101215211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550607635 + 10550607636.

It is an arithmetic number, because the mean of its divisors is an integer number (10550607636).

Almost surely, 2^21101215271 is an apocalyptic number.

21101215271 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101215271 is an equidigital number, since it uses as much as digits as its factorization.

21101215271 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 280, while the sum is 23.

Adding to 21101215271 its reverse (17251210112), we get a palindrome (38352425383).

The spelling of 21101215271 in words is "twenty-one billion, one hundred one million, two hundred fifteen thousand, two hundred seventy-one".