21627389 has 4 divisors (see below), whose sum is σ = 24717024. Its totient is φ = 18537756.

The previous prime is 21627373. The next prime is 21627401. The reversal of 21627389 is 98372612.

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 21627389 - 2⁴ = 21627373 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21623389) 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, 1544807 + ... + 1544820.

It is an arithmetic number, because the mean of its divisors is an integer number (6179256).

Almost surely, 2^21627389 is an apocalyptic number.

It is an amenable number.

21627389 is a deficient number, since it is larger than the sum of its proper divisors (3089635).

21627389 is an equidigital number, since it uses as much as digits as its factorization.

21627389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3089634.

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

The square root of 21627389 is about 4650.5256692120. The cubic root of 21627389 is about 278.6129918510.

The spelling of 21627389 in words is "twenty-one million, six hundred twenty-seven thousand, three hundred eighty-nine".