21018734080 has 160 divisors (see below), whose sum is σ = 52664629248. Its totient is φ = 8035737600.

The previous prime is 21018734053. The next prime is 21018734089. The reversal of 21018734080 is 8043781012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (160).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21018734089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6585285 + ... + 6588475.

Almost surely, 2^21018734080 is an apocalyptic number.

21018734080 is a gapful number since it is divisible by the number (20) 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 21018734080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26332314624).

21018734080 is an abundant number, since it is smaller than the sum of its proper divisors (31645895168).

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

21018734080 is an equidigital number, since it uses as much as digits as its factorization.

21018734080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3328 (or 3312 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 34.

The spelling of 21018734080 in words is "twenty-one billion, eighteen million, seven hundred thirty-four thousand, eighty".