21168767616 has 128 divisors (see below), whose sum is σ = 61230600000. Its totient is φ = 6454296576.

The previous prime is 21168767611. The next prime is 21168767639. The reversal of 21168767616 is 61676786112.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-3 number, since 3×21168767616³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21168767611) 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, 161560 + ... + 261608.

Almost surely, 2^21168767616 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 21168767616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30615300000).

21168767616 is an abundant number, since it is smaller than the sum of its proper divisors (40061832384).

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

21168767616 is a wasteful number, since it uses less digits than its factorization.

21168767616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100114 (or 100102 counting only the distinct ones).

The product of its digits is 1016064, while the sum is 51.

The spelling of 21168767616 in words is "twenty-one billion, one hundred sixty-eight million, seven hundred sixty-seven thousand, six hundred sixteen".