21344424240 has 40 divisors (see below), whose sum is σ = 66167715888. Its totient is φ = 5691846400.

The previous prime is 21344424217. The next prime is 21344424259. The reversal of 21344424240 is 4242444312.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×21344424240² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 21344424198 and 21344424207.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44467311 + ... + 44467790.

Almost surely, 2^21344424240 is an apocalyptic number.

21344424240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21344424240 is an abundant number, since it is smaller than the sum of its proper divisors (44823291648).

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

21344424240 is a wasteful number, since it uses less digits than its factorization.

21344424240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88935117 (or 88935111 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 30.

Adding to 21344424240 its reverse (4242444312), we get a palindrome (25586868552).

The spelling of 21344424240 in words is "twenty-one billion, three hundred forty-four million, four hundred twenty-four thousand, two hundred forty".