21304041520 has 20 divisors (see below), whose sum is σ = 49531896720. Its totient is φ = 8521616576.

The previous prime is 21304041497. The next prime is 21304041553. The reversal of 21304041520 is 2514040312.

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 21304041491 and 21304041500.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 133150180 + ... + 133150339.

It is an arithmetic number, because the mean of its divisors is an integer number (2476594836).

Almost surely, 2^21304041520 is an apocalyptic number.

21304041520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21304041520 is an abundant number, since it is smaller than the sum of its proper divisors (28227855200).

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

21304041520 is a wasteful number, since it uses less digits than its factorization.

21304041520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266300532 (or 266300526 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 22.

Adding to 21304041520 its reverse (2514040312), we get a palindrome (23818081832).

The spelling of 21304041520 in words is "twenty-one billion, three hundred four million, forty-one thousand, five hundred twenty".