21145684279 has 2 divisors, whose sum is σ = 21145684280. Its totient is φ = 21145684278.

The previous prime is 21145684249. The next prime is 21145684327. The reversal of 21145684279 is 97248654112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21145684279 - 2¹⁹ = 21145159991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21145684229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10572842139 + 10572842140.

It is an arithmetic number, because the mean of its divisors is an integer number (10572842140).

Almost surely, 2^21145684279 is an apocalyptic number.

21145684279 is a deficient number, since it is larger than the sum of its proper divisors (1).

21145684279 is an equidigital number, since it uses as much as digits as its factorization.

21145684279 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 21145684279 in words is "twenty-one billion, one hundred forty-five million, six hundred eighty-four thousand, two hundred seventy-nine".