21043053041521 has 32 divisors (see below), whose sum is σ = 24637241502720. Its totient is φ = 17596866603456.

The previous prime is 21043053041509. The next prime is 21043053041539. The reversal of 21043053041521 is 12514035034012.

It is not a de Polignac number, because 21043053041521 - 2²³ = 21043044652913 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21043053044521) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1026129750 + ... + 1026150256.

It is an arithmetic number, because the mean of its divisors is an integer number (769913796960).

Almost surely, 2^{21043053041521} is an apocalyptic number.

It is an amenable number.

21043053041521 is a deficient number, since it is larger than the sum of its proper divisors (3594188461199).

21043053041521 is a wasteful number, since it uses less digits than its factorization.

21043053041521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24373.

The product of its (nonzero) digits is 14400, while the sum is 31.

Adding to 21043053041521 its reverse (12514035034012), we get a palindrome (33557088075533).

The spelling of 21043053041521 in words is "twenty-one trillion, forty-three billion, fifty-three million, forty-one thousand, five hundred twenty-one".