21002401420 has 384 divisors, whose sum is σ = 62629281792. Its totient is φ = 5704473600.

The previous prime is 21002401403. The next prime is 21002401481. The reversal of 21002401420 is 2410420012.

It is a super-2 number, since 2×21002401420² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21002401394 and 21002401403.

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 127 ways as a sum of consecutive naturals, for example, 26686267 + ... + 26687053.

It is an arithmetic number, because the mean of its divisors is an integer number (163097088).

Almost surely, 2^21002401420 is an apocalyptic number.

21002401420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21002401420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31314640896).

21002401420 is an abundant number, since it is smaller than the sum of its proper divisors (41626880372).

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

21002401420 is a wasteful number, since it uses less digits than its factorization.

21002401420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 901 (or 899 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21002401420 its reverse (2410420012), we get a palindrome (23412821432).

The spelling of 21002401420 in words is "twenty-one billion, two million, four hundred one thousand, four hundred twenty".