21269121 has 4 divisors (see below), whose sum is σ = 28358832. Its totient is φ = 14179412.

The previous prime is 21269099. The next prime is 21269123. The reversal of 21269121 is 12196212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21269121 - 2⁷ = 21268993 is a prime.

It is a super-2 number, since 2×21269121² = 904751016225282, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21269091 and 21269100.

It is not an unprimeable number, because it can be changed into a prime (21269123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3544851 + ... + 3544856.

It is an arithmetic number, because the mean of its divisors is an integer number (7089708).

Almost surely, 2^21269121 is an apocalyptic number.

It is an amenable number.

21269121 is a deficient number, since it is larger than the sum of its proper divisors (7089711).

21269121 is an equidigital number, since it uses as much as digits as its factorization.

21269121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7089710.

The product of its digits is 432, while the sum is 24.

The square root of 21269121 is about 4611.8457259540. The cubic root of 21269121 is about 277.0659654267.

The spelling of 21269121 in words is "twenty-one million, two hundred sixty-nine thousand, one hundred twenty-one".