21013432344 has 64 divisors (see below), whose sum is σ = 58390512000. Its totient is φ = 7002093600.

The previous prime is 21013432343. The next prime is 21013432351. The reversal of 21013432344 is 44323431012.

21013432344 is a `hidden beast` number, since 210 + 13 + 432 + 3 + 4 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21013432343) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 689019 + ... + 718869.

It is an arithmetic number, because the mean of its divisors is an integer number (912351750).

Almost surely, 2^21013432344 is an apocalyptic number.

21013432344 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21013432344 is an abundant number, since it is smaller than the sum of its proper divisors (37377079656).

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

21013432344 is a wasteful number, since it uses less digits than its factorization.

21013432344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33125 (or 33115 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

Adding to 21013432344 its reverse (44323431012), we get a palindrome (65336863356).

The spelling of 21013432344 in words is "twenty-one billion, thirteen million, four hundred thirty-two thousand, three hundred forty-four".