821459957888 has 64 divisors (see below), whose sum is σ = 1648511443800. Its totient is φ = 407723286528.

The previous prime is 821459957839. The next prime is 821459957897. The reversal of 821459957888 is 888759954128.

It can be written as a sum of positive squares in 4 ways, for example, as 508209300544 + 313250657344 = 712888^2 + 559688^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-3 number, since 3×821459957888³ (a number of 37 digits) contains 333 as substring.

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 7 ways as a sum of consecutive naturals, for example, 14431628 + ... + 14488436.

Almost surely, 2^821459957888 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 821459957888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (824255721900).

821459957888 is an abundant number, since it is smaller than the sum of its proper divisors (827051485912).

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

821459957888 is a wasteful number, since it uses less digits than its factorization.

821459957888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57649 (or 57637 counting only the distinct ones).

The product of its digits is 464486400, while the sum is 74.

The spelling of 821459957888 in words is "eight hundred twenty-one billion, four hundred fifty-nine million, nine hundred fifty-seven thousand, eight hundred eighty-eight".