21271270761 has 40 divisors (see below), whose sum is σ = 34539873984. Its totient is φ = 12967607520.

The previous prime is 21271270717. The next prime is 21271270771. The reversal of 21271270761 is 16707217212.

It is not a de Polignac number, because 21271270761 - 2⁷ = 21271270633 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21271270771) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 18276 + ... + 207066.

Almost surely, 2^21271270761 is an apocalyptic number.

It is an amenable number.

21271270761 is a deficient number, since it is larger than the sum of its proper divisors (13268603223).

21271270761 is a wasteful number, since it uses less digits than its factorization.

21271270761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188923 (or 188914 counting only the distinct ones).

The product of its (nonzero) digits is 16464, while the sum is 36.

Adding to 21271270761 its reverse (16707217212), we get a palindrome (37978487973).

The spelling of 21271270761 in words is "twenty-one billion, two hundred seventy-one million, two hundred seventy thousand, seven hundred sixty-one".