21506201631304 has 128 divisors (see below), whose sum is σ = 46510393104000. Its totient is φ = 9239355500544.

The previous prime is 21506201631199. The next prime is 21506201631353. The reversal of 21506201631304 is 40313610260512.

It is a self number, because there is not a number n which added to its sum of digits gives 21506201631304.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 229973484 + ... + 230066980.

It is an arithmetic number, because the mean of its divisors is an integer number (363362446125).

Almost surely, 2^{21506201631304} 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 21506201631304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23255196552000).

21506201631304 is an abundant number, since it is smaller than the sum of its proper divisors (25004191472696).

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

21506201631304 is a wasteful number, since it uses less digits than its factorization.

21506201631304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95567 (or 95563 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 34.

Adding to 21506201631304 its reverse (40313610260512), we get a palindrome (61819811891816).

The spelling of 21506201631304 in words is "twenty-one trillion, five hundred six billion, two hundred one million, six hundred thirty-one thousand, three hundred four".