21357016603664 has 160 divisors (see below), whose sum is σ = 49951871566080. Its totient is φ = 8641282922496.

The previous prime is 21357016603639. The next prime is 21357016603709. The reversal of 21357016603664 is 46630661075312.

It is a super-2 number, since 2×21357016603664² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1089800714 + ... + 1089820310.

It is an arithmetic number, because the mean of its divisors is an integer number (312199197288).

Almost surely, 2^{21357016603664} 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 21357016603664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24975935783040).

21357016603664 is an abundant number, since it is smaller than the sum of its proper divisors (28594854962416).

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

21357016603664 is a wasteful number, since it uses less digits than its factorization.

21357016603664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21377 (or 21371 counting only the distinct ones).

The product of its (nonzero) digits is 3265920, while the sum is 50.

Adding to 21357016603664 its reverse (46630661075312), we get a palindrome (67987677678976).

The spelling of 21357016603664 in words is "twenty-one trillion, three hundred fifty-seven billion, sixteen million, six hundred three thousand, six hundred sixty-four".