21920269 has 4 divisors (see below), whose sum is σ = 25051744. Its totient is φ = 18788796.

The previous prime is 21920263. The next prime is 21920279. The reversal of 21920269 is 96202912.

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 21920269 - 2⁷ = 21920141 is a prime.

It is a super-2 number, since 2×21920269² = 960996386064722, 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 21920269.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21920263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1565727 + ... + 1565740.

It is an arithmetic number, because the mean of its divisors is an integer number (6262936).

Almost surely, 2^21920269 is an apocalyptic number.

It is an amenable number.

21920269 is a deficient number, since it is larger than the sum of its proper divisors (3131475).

21920269 is an equidigital number, since it uses as much as digits as its factorization.

21920269 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3131474.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 21920269 is about 4681.9086919760. The cubic root of 21920269 is about 279.8650242302.

The spelling of 21920269 in words is "twenty-one million, nine hundred twenty thousand, two hundred sixty-nine".