21269667 has 4 divisors (see below), whose sum is σ = 28359560. Its totient is φ = 14179776.

The previous prime is 21269659. The next prime is 21269681. The reversal of 21269667 is 76696212.

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

It is not a de Polignac number, because 21269667 - 2³ = 21269659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21269657) 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, 3544942 + ... + 3544947.

It is an arithmetic number, because the mean of its divisors is an integer number (7089890).

Almost surely, 2^21269667 is an apocalyptic number.

21269667 is a deficient number, since it is larger than the sum of its proper divisors (7089893).

21269667 is an equidigital number, since it uses as much as digits as its factorization.

21269667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7089892.

The product of its digits is 54432, while the sum is 39.

The square root of 21269667 is about 4611.9049209627. The cubic root of 21269667 is about 277.0683362616.

The spelling of 21269667 in words is "twenty-one million, two hundred sixty-nine thousand, six hundred sixty-seven".