21430371 has 4 divisors (see below), whose sum is σ = 28573832. Its totient is φ = 14286912.

The previous prime is 21430369. The next prime is 21430379. The reversal of 21430371 is 17303412.

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

It is not a de Polignac number, because 21430371 - 2¹ = 21430369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21430379) 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, 3571726 + ... + 3571731.

It is an arithmetic number, because the mean of its divisors is an integer number (7143458).

Almost surely, 2^21430371 is an apocalyptic number.

21430371 is a deficient number, since it is larger than the sum of its proper divisors (7143461).

21430371 is an equidigital number, since it uses as much as digits as its factorization.

21430371 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7143460.

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 21430371 is about 4629.2948707120. The cubic root of 21430371 is about 277.7643872597.

Adding to 21430371 its reverse (17303412), we get a palindrome (38733783).

The spelling of 21430371 in words is "twenty-one million, four hundred thirty thousand, three hundred seventy-one".