21613321371672 has 256 divisors, whose sum is σ = 64918166400000. Its totient is φ = 6639432468480.

The previous prime is 21613321371589. The next prime is 21613321371673. The reversal of 21613321371672 is 27617312331612.

21613321371672 is a `hidden beast` number, since 2 + 1 + 613 + 3 + 2 + 13 + 7 + 16 + 7 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21613321371673) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 941294272 + ... + 941317232.

It is an arithmetic number, because the mean of its divisors is an integer number (253586587500).

Almost surely, 2^{21613321371672} 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 21613321371672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32459083200000).

21613321371672 is an abundant number, since it is smaller than the sum of its proper divisors (43304845028328).

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

21613321371672 is a wasteful number, since it uses less digits than its factorization.

21613321371672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29231 (or 29221 counting only the distinct ones).

The product of its digits is 381024, while the sum is 45.

The spelling of 21613321371672 in words is "twenty-one trillion, six hundred thirteen billion, three hundred twenty-one million, three hundred seventy-one thousand, six hundred seventy-two".