21274847881 has 27 divisors (see below), whose sum is σ = 25204224717. Its totient is φ = 17905650840.

The previous prime is 21274847873. The next prime is 21274847977. The reversal of 21274847881 is 18874847212.

The square root of 21274847881 is 145859.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 21274847881 - 2³ = 21274847873 is a prime.

It is a super-2 number, since 2×21274847881² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21274847851) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 68407716 + ... + 68408026.

Almost surely, 2^21274847881 is an apocalyptic number.

21274847881 is the 145859-th square number.

21274847881 is the 72930-th centered octagonal number.

It is an amenable number.

21274847881 is a deficient number, since it is larger than the sum of its proper divisors (3929376836).

21274847881 is an frugal number, since it uses more digits than its factorization.

21274847881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 770 (or 385 counting only the distinct ones).

The product of its digits is 1605632, while the sum is 52.

The spelling of 21274847881 in words is "twenty-one billion, two hundred seventy-four million, eight hundred forty-seven thousand, eight hundred eighty-one".