21516304321463 has 4 divisors (see below), whose sum is σ = 24590062081680. Its totient is φ = 18442546561248.

The previous prime is 21516304321417. The next prime is 21516304321471. The reversal of 21516304321463 is 36412340361512.

It is a happy number.

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 21516304321463 - 2²² = 21516300127159 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 21516304321463.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21516304321403) 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, 1536878880098 + ... + 1536878880111.

It is an arithmetic number, because the mean of its divisors is an integer number (6147515520420).

Almost surely, 2^{21516304321463} is an apocalyptic number.

21516304321463 is a deficient number, since it is larger than the sum of its proper divisors (3073757760217).

21516304321463 is an equidigital number, since it uses as much as digits as its factorization.

21516304321463 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3073757760216.

The product of its (nonzero) digits is 311040, while the sum is 41.

Adding to 21516304321463 its reverse (36412340361512), we get a palindrome (57928644682975).

The spelling of 21516304321463 in words is "twenty-one trillion, five hundred sixteen billion, three hundred four million, three hundred twenty-one thousand, four hundred sixty-three".