21725807559456 has 3456 divisors, whose sum is σ = 89185001342976. Its totient is φ = 4539828142080.

The previous prime is 21725807559397. The next prime is 21725807559509. The reversal of 21725807559456 is 65495570852712.

It is a happy number.

It is a super-2 number, since 2×21725807559456² (a number of 27 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (66) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 575 ways as a sum of consecutive naturals, for example, 192263783656 + ... + 192263783768.

It is an arithmetic number, because the mean of its divisors is an integer number (25805845296).

Almost surely, 2^{21725807559456} is an apocalyptic number.

21725807559456 is a gapful number since it is divisible by the number (26) 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 21725807559456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44592500671488).

21725807559456 is an abundant number, since it is smaller than the sum of its proper divisors (67459193783520).

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

21725807559456 is a wasteful number, since it uses less digits than its factorization.

21725807559456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264 (or 232 counting only the distinct ones).

The product of its (nonzero) digits is 211680000, while the sum is 66.

The spelling of 21725807559456 in words is "twenty-one trillion, seven hundred twenty-five billion, eight hundred seven million, five hundred fifty-nine thousand, four hundred fifty-six".