21111693616 has 80 divisors (see below), whose sum is σ = 44669363200. Its totient is φ = 9665091072.

The previous prime is 21111693613. The next prime is 21111693653. The reversal of 21111693616 is 61639611112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111693613) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4461940 + ... + 4466668.

It is an arithmetic number, because the mean of its divisors is an integer number (558367040).

Almost surely, 2^21111693616 is an apocalyptic number.

21111693616 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21111693616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22334681600).

21111693616 is an abundant number, since it is smaller than the sum of its proper divisors (23557669584).

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

21111693616 is a wasteful number, since it uses less digits than its factorization.

21111693616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4903 (or 4871 counting only the distinct ones).

The product of its digits is 11664, while the sum is 37.

The spelling of 21111693616 in words is "twenty-one billion, one hundred eleven million, six hundred ninety-three thousand, six hundred sixteen".