21081330456479 has 4 divisors (see below), whose sum is σ = 21081642890880. Its totient is φ = 21081018022080.

The previous prime is 21081330456443. The next prime is 21081330456491. The reversal of 21081330456479 is 97465403318012.

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 21081330456479 - 2⁸ = 21081330456223 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21081330456479.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21081330459479) 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, 156115967 + ... + 156250944.

It is an arithmetic number, because the mean of its divisors is an integer number (5270410722720).

It is a 1-persistent number, because it is pandigital, but 2⋅21081330456479 = 42162660912958 is not.

Almost surely, 2^{21081330456479} is an apocalyptic number.

21081330456479 is a deficient number, since it is larger than the sum of its proper divisors (312434401).

21081330456479 is an equidigital number, since it uses as much as digits as its factorization.

21081330456479 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312434400.

The product of its (nonzero) digits is 4354560, while the sum is 53.

The spelling of 21081330456479 in words is "twenty-one trillion, eighty-one billion, three hundred thirty million, four hundred fifty-six thousand, four hundred seventy-nine".