21152421345 has 64 divisors (see below), whose sum is σ = 37240197120. Its totient is φ = 10167360000.

The previous prime is 21152421341. The next prime is 21152421349. The reversal of 21152421345 is 54312425112.

It is an interprime number because it is at equal distance from previous prime (21152421341) and next prime (21152421349).

It is not a de Polignac number, because 21152421345 - 2² = 21152421341 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21152421341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 9897117 + ... + 9899253.

It is an arithmetic number, because the mean of its divisors is an integer number (581878080).

Almost surely, 2^21152421345 is an apocalyptic number.

It is an amenable number.

21152421345 is a deficient number, since it is larger than the sum of its proper divisors (16087775775).

21152421345 is a wasteful number, since it uses less digits than its factorization.

21152421345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2646.

The product of its digits is 9600, while the sum is 30.

Adding to 21152421345 its reverse (54312425112), we get a palindrome (75464846457).

The spelling of 21152421345 in words is "twenty-one billion, one hundred fifty-two million, four hundred twenty-one thousand, three hundred forty-five".