21013214440 has 16 divisors (see below), whose sum is σ = 47279732580. Its totient is φ = 8405285760.

The previous prime is 21013214423. The next prime is 21013214447. The reversal of 21013214440 is 4441231012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 19792550596 + 1220663844 = 140686^2 + 34938^2 .

It is a super-2 number, since 2×21013214440² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21013214447) 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 3 ways as a sum of consecutive naturals, for example, 262665141 + ... + 262665220.

Almost surely, 2^21013214440 is an apocalyptic number.

21013214440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21013214440 is an abundant number, since it is smaller than the sum of its proper divisors (26266518140).

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

21013214440 is a wasteful number, since it uses less digits than its factorization.

21013214440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525330372 (or 525330368 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 21013214440 its reverse (4441231012), we get a palindrome (25454445452).

The spelling of 21013214440 in words is "twenty-one billion, thirteen million, two hundred fourteen thousand, four hundred forty".