21725771280 has 160 divisors (see below), whose sum is σ = 67990315008. Its totient is φ = 5738688000.

The previous prime is 21725771269. The next prime is 21725771321. The reversal of 21725771280 is 8217752712.

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 31 ways as a sum of consecutive naturals, for example, 17648265 + ... + 17649495.

Almost surely, 2^21725771280 is an apocalyptic number.

21725771280 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 21725771280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33995157504).

21725771280 is an abundant number, since it is smaller than the sum of its proper divisors (46264543728).

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

21725771280 is a wasteful number, since it uses less digits than its factorization.

21725771280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1885 (or 1879 counting only the distinct ones).

The product of its (nonzero) digits is 109760, while the sum is 42.

The spelling of 21725771280 in words is "twenty-one billion, seven hundred twenty-five million, seven hundred seventy-one thousand, two hundred eighty".