21404444140 has 24 divisors (see below), whose sum is σ = 46399312512. Its totient is φ = 8285591040.

The previous prime is 21404444137. The next prime is 21404444143. The reversal of 21404444140 is 4144440412.

It is an interprime number because it is at equal distance from previous prime (21404444137) and next prime (21404444143).

It is a junction number, because it is equal to n+sod(n) for n = 21404444099 and 21404444108.

It is not an unprimeable number, because it can be changed into a prime (21404444143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17261029 + ... + 17262268.

It is an arithmetic number, because the mean of its divisors is an integer number (1933304688).

Almost surely, 2^21404444140 is an apocalyptic number.

21404444140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21404444140 is an abundant number, since it is smaller than the sum of its proper divisors (24994868372).

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

21404444140 is a wasteful number, since it uses less digits than its factorization.

21404444140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34523337 (or 34523335 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 28.

Adding to 21404444140 its reverse (4144440412), we get a palindrome (25548884552).

The spelling of 21404444140 in words is "twenty-one billion, four hundred four million, four hundred forty-four thousand, one hundred forty".