21335318887 has 2 divisors, whose sum is σ = 21335318888. Its totient is φ = 21335318886.

The previous prime is 21335318863. The next prime is 21335318951. The reversal of 21335318887 is 78881353312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21335318887 - 2²³ = 21326930279 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21335318887.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21335318287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10667659443 + 10667659444.

It is an arithmetic number, because the mean of its divisors is an integer number (10667659444).

Almost surely, 2^21335318887 is an apocalyptic number.

21335318887 is a deficient number, since it is larger than the sum of its proper divisors (1).

21335318887 is an equidigital number, since it uses as much as digits as its factorization.

21335318887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 967680, while the sum is 49.

The spelling of 21335318887 in words is "twenty-one billion, three hundred thirty-five million, three hundred eighteen thousand, eight hundred eighty-seven".