21043111499 has 2 divisors, whose sum is σ = 21043111500. Its totient is φ = 21043111498.

The previous prime is 21043111471. The next prime is 21043111511. The reversal of 21043111499 is 99411134012.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21043111499 is a prime.

It is not a weakly prime, because it can be changed into another prime (21043111469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10521555749 + 10521555750.

It is an arithmetic number, because the mean of its divisors is an integer number (10521555750).

Almost surely, 2^21043111499 is an apocalyptic number.

21043111499 is a deficient number, since it is larger than the sum of its proper divisors (1).

21043111499 is an equidigital number, since it uses as much as digits as its factorization.

21043111499 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 35.

The spelling of 21043111499 in words is "twenty-one billion, forty-three million, one hundred eleven thousand, four hundred ninety-nine".