21272881 has 8 divisors (see below), whose sum is σ = 24504320. Its totient is φ = 18089568.

The previous prime is 21272843. The next prime is 21272947. The reversal of 21272881 is 18827212.

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

It is not a de Polignac number, because 21272881 - 2¹³ = 21264689 is a prime.

It is a super-2 number, since 2×21272881² = 905070932080322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21272821) 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, 11076 + ... + 12853.

It is an arithmetic number, because the mean of its divisors is an integer number (3063040).

Almost surely, 2^21272881 is an apocalyptic number.

It is an amenable number.

21272881 is a deficient number, since it is larger than the sum of its proper divisors (3231439).

21272881 is a wasteful number, since it uses less digits than its factorization.

21272881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24063.

The product of its digits is 3584, while the sum is 31.

The square root of 21272881 is about 4612.2533538391. The cubic root of 21272881 is about 277.0822912329.

The spelling of 21272881 in words is "twenty-one million, two hundred seventy-two thousand, eight hundred eighty-one".