21145515421303 has 24 divisors (see below), whose sum is σ = 26498243817360. Its totient is φ = 16725302455680.

The previous prime is 21145515421211. The next prime is 21145515421337. The reversal of 21145515421303 is 30312451554112.

It is a de Polignac number, because none of the positive numbers 2^k-21145515421303 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21145515421343) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3128113 + ... + 7216378.

It is an arithmetic number, because the mean of its divisors is an integer number (1104093492390).

Almost surely, 2^{21145515421303} is an apocalyptic number.

21145515421303 is a deficient number, since it is larger than the sum of its proper divisors (5352728396057).

21145515421303 is a wasteful number, since it uses less digits than its factorization.

21145515421303 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10347727 (or 10347720 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 37.

Adding to 21145515421303 its reverse (30312451554112), we get a palindrome (51457966975415).

The spelling of 21145515421303 in words is "twenty-one trillion, one hundred forty-five billion, five hundred fifteen million, four hundred twenty-one thousand, three hundred three".