21421143443440 has 40 divisors (see below), whose sum is σ = 53635247624448. Its totient is φ = 7909345271040.

The previous prime is 21421143443437. The next prime is 21421143443473. The reversal of 21421143443440 is 4434434112412.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21421143443440.

It is a congruent number.

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, 10298625616 + ... + 10298627695.

Almost surely, 2^{21421143443440} is an apocalyptic number.

21421143443440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21421143443440 is an abundant number, since it is smaller than the sum of its proper divisors (32214104181008).

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

21421143443440 is a wasteful number, since it uses less digits than its factorization.

21421143443440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20597253337 (or 20597253331 counting only the distinct ones).

The product of its (nonzero) digits is 147456, while the sum is 37.

Adding to 21421143443440 its reverse (4434434112412), we get a palindrome (25855577555852).

The spelling of 21421143443440 in words is "twenty-one trillion, four hundred twenty-one billion, one hundred forty-three million, four hundred forty-three thousand, four hundred forty".