21303221240 has 64 divisors (see below), whose sum is σ = 54916608960. Its totient is φ = 7285708800.

The previous prime is 21303221231. The next prime is 21303221323. The reversal of 21303221240 is 4212230312.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17414 + ... + 207146.

It is an arithmetic number, because the mean of its divisors is an integer number (858072015).

Almost surely, 2^21303221240 is an apocalyptic number.

21303221240 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 21303221240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27458304480).

21303221240 is an abundant number, since it is smaller than the sum of its proper divisors (33613387720).

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

21303221240 is a wasteful number, since it uses less digits than its factorization.

21303221240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190152 (or 190148 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21303221240 its reverse (4212230312), we get a palindrome (25515451552).

The spelling of 21303221240 in words is "twenty-one billion, three hundred three million, two hundred twenty-one thousand, two hundred forty".