21420140144 has 20 divisors (see below), whose sum is σ = 44693946696. Its totient is φ = 9886218432.

The previous prime is 21420140129. The next prime is 21420140171. The reversal of 21420140144 is 44104102412.

It is a super-4 number, since 4×21420140144⁴ (a number of 42 digits) contains 4444 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51490514 + ... + 51490929.

Almost surely, 2^21420140144 is an apocalyptic number.

It is an amenable number.

21420140144 is an abundant number, since it is smaller than the sum of its proper divisors (23273806552).

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

21420140144 is a wasteful number, since it uses less digits than its factorization.

21420140144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102981464 (or 102981458 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 23.

Adding to 21420140144 its reverse (44104102412), we get a palindrome (65524242556).

The spelling of 21420140144 in words is "twenty-one billion, four hundred twenty million, one hundred forty thousand, one hundred forty-four".