21002221240 has 192 divisors, whose sum is σ = 64581118560. Its totient is φ = 6042516480.

The previous prime is 21002221223. The next prime is 21002221301. The reversal of 21002221240 is 4212220012.

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 47 ways as a sum of consecutive naturals, for example, 242814 + ... + 317746.

Almost surely, 2^21002221240 is an apocalyptic number.

21002221240 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 21002221240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32290559280).

21002221240 is an abundant number, since it is smaller than the sum of its proper divisors (43578897320).

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

21002221240 is a wasteful number, since it uses less digits than its factorization.

21002221240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74982 (or 74971 counting only the distinct ones).

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

Adding to 21002221240 its reverse (4212220012), we get a palindrome (25214441252).

It can be divided in two parts, 21002 and 221240, that added together give a palindrome (242242).

The spelling of 21002221240 in words is "twenty-one billion, two million, two hundred twenty-one thousand, two hundred forty".