21255189760 has 288 divisors, whose sum is σ = 62940810240. Its totient is φ = 6710624256.

The previous prime is 21255189737. The next prime is 21255189763. The reversal of 21255189760 is 6798155212.

21255189760 = T₁₈₈₄₁ + T₁₈₈₄₂ + ... + T₁₈₉₅₉.

It is a self number, because there is not a number n which added to its sum of digits gives 21255189760.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21255189763) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7157556 + ... + 7160524.

It is an arithmetic number, because the mean of its divisors is an integer number (218544480).

Almost surely, 2^21255189760 is an apocalyptic number.

21255189760 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 21255189760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31470405120).

21255189760 is an abundant number, since it is smaller than the sum of its proper divisors (41685620480).

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

21255189760 is a wasteful number, since it uses less digits than its factorization.

21255189760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3061 (or 3047 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 46.

The spelling of 21255189760 in words is "twenty-one billion, two hundred fifty-five million, one hundred eighty-nine thousand, seven hundred sixty".