21820169088 has 192 divisors, whose sum is σ = 66936480000. Its totient is φ = 6802818048.

The previous prime is 21820169047. The next prime is 21820169089. The reversal of 21820169088 is 88096102812.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (192).

It is a super-2 number, since 2×21820169088² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21820169089) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1722843 + ... + 1735461.

It is an arithmetic number, because the mean of its divisors is an integer number (348627500).

Almost surely, 2^21820169088 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 21820169088, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33468240000).

21820169088 is an abundant number, since it is smaller than the sum of its proper divisors (45116310912).

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

21820169088 is a wasteful number, since it uses less digits than its factorization.

21820169088 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12737 (or 12722 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 45.

The spelling of 21820169088 in words is "twenty-one billion, eight hundred twenty million, one hundred sixty-nine thousand, eighty-eight".