21240121350 has 192 divisors, whose sum is σ = 61138944000. Its totient is φ = 4779855360.

The previous prime is 21240121339. The next prime is 21240121411. The reversal of 21240121350 is 5312104212.

It is a super-2 number, since 2×21240121350² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 19868616 + ... + 19869684.

It is an arithmetic number, because the mean of its divisors is an integer number (318432000).

Almost surely, 2^21240121350 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21240121350, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30569472000).

21240121350 is an abundant number, since it is smaller than the sum of its proper divisors (39898822650).

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

21240121350 is a wasteful number, since it uses less digits than its factorization.

21240121350 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1367 (or 1362 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

Adding to 21240121350 its reverse (5312104212), we get a palindrome (26552225562).

The spelling of 21240121350 in words is "twenty-one billion, two hundred forty million, one hundred twenty-one thousand, three hundred fifty".