21545366480 has 120 divisors (see below), whose sum is σ = 55550960136. Its totient is φ = 7764951040.

The previous prime is 21545366467. The next prime is 21545366509. The reversal of 21545366480 is 8466354512.

It can be written as a sum of positive squares in 4 ways, for example, as 932447296 + 20612919184 = 30536^2 + 143572^2 .

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 1083992 + ... + 1103688.

Almost surely, 2^21545366480 is an apocalyptic number.

21545366480 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 21545366480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27775480068).

21545366480 is an abundant number, since it is smaller than the sum of its proper divisors (34005593656).

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

21545366480 is a wasteful number, since it uses less digits than its factorization.

21545366480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19845 (or 19828 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 44.

The spelling of 21545366480 in words is "twenty-one billion, five hundred forty-five million, three hundred sixty-six thousand, four hundred eighty".