21434071 has 4 divisors (see below), whose sum is σ = 22562200. Its totient is φ = 20305944.

The previous prime is 21434053. The next prime is 21434099. The reversal of 21434071 is 17043412.

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 21434071 - 2¹¹ = 21432023 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21434471) 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, 564036 + ... + 564073.

It is an arithmetic number, because the mean of its divisors is an integer number (5640550).

Almost surely, 2^21434071 is an apocalyptic number.

21434071 is a deficient number, since it is larger than the sum of its proper divisors (1128129).

21434071 is a wasteful number, since it uses less digits than its factorization.

21434071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1128128.

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 21434071 is about 4629.6944823606. The cubic root of 21434071 is about 277.7803718810.

Adding to 21434071 its reverse (17043412), we get a palindrome (38477483).

The spelling of 21434071 in words is "twenty-one million, four hundred thirty-four thousand, seventy-one".