21167102784 has 112 divisors (see below), whose sum is σ = 58006609920. Its totient is φ = 6804080640.

The previous prime is 21167102773. The next prime is 21167102797. The reversal of 21167102784 is 48720176112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5905857 + ... + 5909439.

It is an arithmetic number, because the mean of its divisors is an integer number (517916160).

Almost surely, 2^21167102784 is an apocalyptic number.

21167102784 is a gapful number since it is divisible by the number (24) 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 21167102784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29003304960).

21167102784 is an abundant number, since it is smaller than the sum of its proper divisors (36839507136).

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

21167102784 is a wasteful number, since it uses less digits than its factorization.

21167102784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4688 (or 4678 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 39.

Adding to 21167102784 its reverse (48720176112), we get a palindrome (69887278896).

The spelling of 21167102784 in words is "twenty-one billion, one hundred sixty-seven million, one hundred two thousand, seven hundred eighty-four".