21988885212 has 288 divisors, whose sum is σ = 72866572800. Its totient is φ = 5600710656.

The previous prime is 21988885207. The next prime is 21988885253. The reversal of 21988885212 is 21258888912.

It is a happy number.

21988885212 is a `hidden beast` number, since 21 + 98 + 8 + 8 + 8 + 521 + 2 = 666.

It is a super-2 number, since 2×21988885212² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4148548 + ... + 4153844.

Almost surely, 2^21988885212 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 21988885212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36433286400).

21988885212 is an abundant number, since it is smaller than the sum of its proper divisors (50877687588).

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

21988885212 is a wasteful number, since it uses less digits than its factorization.

21988885212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5370 (or 5345 counting only the distinct ones).

The product of its digits is 1474560, while the sum is 54.

The spelling of 21988885212 in words is "twenty-one billion, nine hundred eighty-eight million, eight hundred eighty-five thousand, two hundred twelve".