21213320440 has 64 divisors (see below), whose sum is σ = 53636385600. Its totient is φ = 7492058112.

The previous prime is 21213320399. The next prime is 21213320449. The reversal of 21213320440 is 4402331212.

It is a super-3 number, since 3×21213320440³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213320449) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 874885 + ... + 898804.

It is an arithmetic number, because the mean of its divisors is an integer number (838068525).

Almost surely, 2^21213320440 is an apocalyptic number.

21213320440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21213320440 is an abundant number, since it is smaller than the sum of its proper divisors (32423065160).

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

21213320440 is a wasteful number, since it uses less digits than its factorization.

21213320440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1773736 (or 1773732 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

Adding to 21213320440 its reverse (4402331212), we get a palindrome (25615651652).

The spelling of 21213320440 in words is "twenty-one billion, two hundred thirteen million, three hundred twenty thousand, four hundred forty".