21269347 has 4 divisors (see below), whose sum is σ = 23202936. Its totient is φ = 19335760.

The previous prime is 21269321. The next prime is 21269357. The reversal of 21269347 is 74396212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21269347 - 2¹⁹ = 20745059 is a prime.

It is a super-3 number, since 3×21269347³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21269357) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 966778 + ... + 966799.

It is an arithmetic number, because the mean of its divisors is an integer number (5800734).

Almost surely, 2^21269347 is an apocalyptic number.

21269347 is a deficient number, since it is larger than the sum of its proper divisors (1933589).

21269347 is a wasteful number, since it uses less digits than its factorization.

21269347 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1933588.

The product of its digits is 18144, while the sum is 34.

The square root of 21269347 is about 4611.8702280095. The cubic root of 21269347 is about 277.0669467662.

The spelling of 21269347 in words is "twenty-one million, two hundred sixty-nine thousand, three hundred forty-seven".