21537226212072 has 256 divisors, whose sum is σ = 59204722176000. Its totient is φ = 6505808974848.

The previous prime is 21537226212067. The next prime is 21537226212083. The reversal of 21537226212072 is 27021262273512.

It is a super-2 number, since 2×21537226212072² (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 (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 218707198 + ... + 218805650.

It is an arithmetic number, because the mean of its divisors is an integer number (231268446000).

Almost surely, 2^{21537226212072} 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 21537226212072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29602361088000).

21537226212072 is an abundant number, since it is smaller than the sum of its proper divisors (37667495963928).

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

21537226212072 is a wasteful number, since it uses less digits than its factorization.

21537226212072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98760 (or 98756 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 42.

Adding to 21537226212072 its reverse (27021262273512), we get a palindrome (48558488485584).

The spelling of 21537226212072 in words is "twenty-one trillion, five hundred thirty-seven billion, two hundred twenty-six million, two hundred twelve thousand, seventy-two".