21075643260 has 384 divisors, whose sum is σ = 79459860480. Its totient is φ = 4534963200.

The previous prime is 21075643207. The next prime is 21075643271. The reversal of 21075643260 is 6234657012.

21075643260 is a `hidden beast` number, since 2 + 1 + 0 + 7 + 5 + 643 + 2 + 6 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 4333230 + ... + 4338090.

It is an arithmetic number, because the mean of its divisors is an integer number (206926720).

Almost surely, 2^21075643260 is an apocalyptic number.

21075643260 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 21075643260, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39729930240).

21075643260 is an abundant number, since it is smaller than the sum of its proper divisors (58384217220).

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

21075643260 is a wasteful number, since it uses less digits than its factorization.

21075643260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4954 (or 4946 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

It can be divided in two parts, 210756 and 43260, that added together give a square (254016 = 504²).

The spelling of 21075643260 in words is "twenty-one billion, seventy-five million, six hundred forty-three thousand, two hundred sixty".