21320444513442 has 16 divisors (see below), whose sum is σ = 42640994112192. Its totient is φ = 7106797323600.

The previous prime is 21320444513383. The next prime is 21320444513443. The reversal of 21320444513442 is 24431544402312.

It is a super-2 number, since 2×21320444513442² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21320444513442.

It is not an unprimeable number, because it can be changed into a prime (21320444513443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1605973 + ... + 6724584.

It is an arithmetic number, because the mean of its divisors is an integer number (2665062132012).

Almost surely, 2^{21320444513442} is an apocalyptic number.

21320444513442 is an abundant number, since it is smaller than the sum of its proper divisors (21320549598750).

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

21320444513442 is a wasteful number, since it uses less digits than its factorization.

21320444513442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8757113.

The product of its (nonzero) digits is 368640, while the sum is 39.

Adding to 21320444513442 its reverse (24431544402312), we get a palindrome (45751988915754).

The spelling of 21320444513442 in words is "twenty-one trillion, three hundred twenty billion, four hundred forty-four million, five hundred thirteen thousand, four hundred forty-two".