21269881 has 8 divisors (see below), whose sum is σ = 21633920. Its totient is φ = 20908368.

The previous prime is 21269879. The next prime is 21269903. The reversal of 21269881 is 18896212.

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

It is a cyclic number.

It is not a de Polignac number, because 21269881 - 2¹ = 21269879 is a prime.

It is a super-2 number, since 2×21269881² = 904815675508322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21269881.

It is not an unprimeable number, because it can be changed into a prime (21269851) 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, 23815 + ... + 24691.

It is an arithmetic number, because the mean of its divisors is an integer number (2704240).

Almost surely, 2^21269881 is an apocalyptic number.

It is an amenable number.

21269881 is a deficient number, since it is larger than the sum of its proper divisors (364039).

21269881 is an equidigital number, since it uses as much as digits as its factorization.

21269881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1263.

The product of its digits is 13824, while the sum is 37.

The square root of 21269881 is about 4611.9281217296. The cubic root of 21269881 is about 277.0692654788.

The spelling of 21269881 in words is "twenty-one million, two hundred sixty-nine thousand, eight hundred eighty-one".