21769835520 has 352 divisors, whose sum is σ = 74239089408. Its totient is φ = 5425856512.

The previous prime is 21769835513. The next prime is 21769835531. The reversal of 21769835520 is 2553896712.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 21769835520.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 68674402 + ... + 68674718.

It is an arithmetic number, because the mean of its divisors is an integer number (210906504).

Almost surely, 2^21769835520 is an apocalyptic number.

21769835520 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 21769835520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37119544704).

21769835520 is an abundant number, since it is smaller than the sum of its proper divisors (52469253888).

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

21769835520 is a wasteful number, since it uses less digits than its factorization.

21769835520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 625 (or 607 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 48.

The spelling of 21769835520 in words is "twenty-one billion, seven hundred sixty-nine million, eight hundred thirty-five thousand, five hundred twenty".