21154043411 has 4 divisors (see below), whose sum is σ = 21725774352. Its totient is φ = 20582312472.

The previous prime is 21154043389. The next prime is 21154043429. The reversal of 21154043411 is 11434045112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21154043411 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21154043461) 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, 285865415 + ... + 285865488.

It is an arithmetic number, because the mean of its divisors is an integer number (5431443588).

Almost surely, 2^21154043411 is an apocalyptic number.

21154043411 is a deficient number, since it is larger than the sum of its proper divisors (571730941).

21154043411 is an equidigital number, since it uses as much as digits as its factorization.

21154043411 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571730940.

The product of its (nonzero) digits is 1920, while the sum is 26.

Adding to 21154043411 its reverse (11434045112), we get a palindrome (32588088523).

The spelling of 21154043411 in words is "twenty-one billion, one hundred fifty-four million, forty-three thousand, four hundred eleven".