21420121024 has 28 divisors (see below), whose sum is σ = 42510835984. Its totient is φ = 10708729344.

The previous prime is 21420121003. The next prime is 21420121039. The reversal of 21420121024 is 42012102412.

It is a junction number, because it is equal to n+sod(n) for n = 21420120992 and 21420121010.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 682444 + ... + 713140.

Almost surely, 2^21420121024 is an apocalyptic number.

It is an amenable number.

21420121024 is a deficient number, since it is larger than the sum of its proper divisors (21090714960).

21420121024 is a wasteful number, since it uses less digits than its factorization.

21420121024 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41612 (or 41602 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 21420121024 its reverse (42012102412), we get a palindrome (63432223436).

It can be divided in two parts, 214201 and 21024, that added together give a square (235225 = 485²).

The spelling of 21420121024 in words is "twenty-one billion, four hundred twenty million, one hundred twenty-one thousand, twenty-four".