21369827 has 4 divisors (see below), whose sum is σ = 21394296. Its totient is φ = 21345360.

The previous prime is 21369811. The next prime is 21369847. The reversal of 21369827 is 72896312.

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 21369827 - 2⁴ = 21369811 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21369847) 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, 10874 + ... + 12687.

It is an arithmetic number, because the mean of its divisors is an integer number (5348574).

Almost surely, 2^21369827 is an apocalyptic number.

21369827 is a deficient number, since it is larger than the sum of its proper divisors (24469).

21369827 is an equidigital number, since it uses as much as digits as its factorization.

21369827 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24468.

The product of its digits is 36288, while the sum is 38.

The square root of 21369827 is about 4622.7510207667. The cubic root of 21369827 is about 277.5025652443.

The spelling of 21369827 in words is "twenty-one million, three hundred sixty-nine thousand, eight hundred twenty-seven".