21258838560 has 192 divisors, whose sum is σ = 70677774720. Its totient is φ = 5356339200.

The previous prime is 21258838543. The next prime is 21258838561. The reversal of 21258838560 is 6583885212.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (21258838561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3654214 + ... + 3660026.

It is an arithmetic number, because the mean of its divisors is an integer number (368113410).

Almost surely, 2^21258838560 is an apocalyptic number.

21258838560 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 21258838560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35338887360).

21258838560 is an abundant number, since it is smaller than the sum of its proper divisors (49418936160).

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

21258838560 is a wasteful number, since it uses less digits than its factorization.

21258838560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6251 (or 6243 counting only the distinct ones).

The product of its (nonzero) digits is 921600, while the sum is 48.

The spelling of 21258838560 in words is "twenty-one billion, two hundred fifty-eight million, eight hundred thirty-eight thousand, five hundred sixty".