21024434111 has 4 divisors (see below), whose sum is σ = 21043496352. Its totient is φ = 21005371872.

The previous prime is 21024434077. The next prime is 21024434117. The reversal of 21024434111 is 11143442012.

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 21024434111 - 2⁶ = 21024434047 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 (21024434117) 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, 9529466 + ... + 9531671.

It is an arithmetic number, because the mean of its divisors is an integer number (5260874088).

Almost surely, 2^21024434111 is an apocalyptic number.

21024434111 is a deficient number, since it is larger than the sum of its proper divisors (19062241).

21024434111 is a wasteful number, since it uses less digits than its factorization.

21024434111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19062240.

The product of its (nonzero) digits is 768, while the sum is 23.

Adding to 21024434111 its reverse (11143442012), we get a palindrome (32167876123).

The spelling of 21024434111 in words is "twenty-one billion, twenty-four million, four hundred thirty-four thousand, one hundred eleven".