21154880000 has 100 divisors (see below), whose sum is σ = 52819443930. Its totient is φ = 8461824000.

The previous prime is 21154879969. The next prime is 21154880011. The reversal of 21154880000 is 8845112.

It can be written as a sum of positive squares in 5 ways, for example, as 781314304 + 20373565696 = 27952^2 + 142736^2 .

It is a tau number, because it is divible by the number of its divisors (100).

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 286946 + ... + 353054.

Almost surely, 2^21154880000 is an apocalyptic number.

21154880000 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 21154880000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26409721965).

21154880000 is an abundant number, since it is smaller than the sum of its proper divisors (31664563930).

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

21154880000 is an frugal number, since it uses more digits than its factorization.

21154880000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66147 (or 66116 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 29.

The spelling of 21154880000 in words is "twenty-one billion, one hundred fifty-four million, eight hundred eighty thousand".