21571280640 has 1152 divisors, whose sum is σ = 99446323200. Its totient is φ = 4311760896.

The previous prime is 21571280629. The next prime is 21571280651. The reversal of 21571280640 is 4608217512.

21571280640 is a `hidden beast` number, since 2 + 1 + 5 + 7 + 1 + 2 + 8 + 0 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (21571280629) and next prime (21571280651).

It is a tau number, because it is divible by the number of its divisors (1152).

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

It is a junction number, because it is equal to n+sod(n) for n = 21571280595 and 21571280604.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1135330551 + ... + 1135330569.

Almost surely, 2^21571280640 is an apocalyptic number.

21571280640 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 21571280640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49723161600).

21571280640 is an abundant number, since it is smaller than the sum of its proper divisors (77875042560).

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

21571280640 is an equidigital number, since it uses as much as digits as its factorization.

21571280640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107 (or 49 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The spelling of 21571280640 in words is "twenty-one billion, five hundred seventy-one million, two hundred eighty thousand, six hundred forty".