21434971 has 4 divisors (see below), whose sum is σ = 21736944. Its totient is φ = 21133000.

The previous prime is 21434957. The next prime is 21435017. The reversal of 21434971 is 17943412.

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 21434971 - 2⁵ = 21434939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21434911) 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, 150880 + ... + 151021.

It is an arithmetic number, because the mean of its divisors is an integer number (5434236).

Almost surely, 2^21434971 is an apocalyptic number.

21434971 is a deficient number, since it is larger than the sum of its proper divisors (301973).

21434971 is an equidigital number, since it uses as much as digits as its factorization.

21434971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301972.

The product of its digits is 6048, while the sum is 31.

The square root of 21434971 is about 4629.7916799787. The cubic root of 21434971 is about 277.7842597539.

The spelling of 21434971 in words is "twenty-one million, four hundred thirty-four thousand, nine hundred seventy-one".