21152516222464 has 160 divisors (see below), whose sum is σ = 48899193108480. Its totient is φ = 9045976473600.

The previous prime is 21152516222437. The next prime is 21152516222471. The reversal of 21152516222464 is 46422261525112.

It is a self number, because there is not a number n which added to its sum of digits gives 21152516222464.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6563217 + ... + 9240175.

It is an arithmetic number, because the mean of its divisors is an integer number (305619956928).

Almost surely, 2^{21152516222464} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21152516222464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24449596554240).

21152516222464 is an abundant number, since it is smaller than the sum of its proper divisors (27746676886016).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21152516222464 is a wasteful number, since it uses less digits than its factorization.

21152516222464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2677072 (or 2677056 counting only the distinct ones).

The product of its digits is 460800, while the sum is 43.

Adding to 21152516222464 its reverse (46422261525112), we get a palindrome (67574777747576).

The spelling of 21152516222464 in words is "twenty-one trillion, one hundred fifty-two billion, five hundred sixteen million, two hundred twenty-two thousand, four hundred sixty-four".