21021214515523 has 12 divisors (see below), whose sum is σ = 22442469483168. Its totient is φ = 19679434842320.

The previous prime is 21021214515467. The next prime is 21021214515533. The reversal of 21021214515523 is 32551541212012.

It is not a de Polignac number, because 21021214515523 - 2⁹ = 21021214515011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21021214515533) 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 11 ways as a sum of consecutive naturals, for example, 422716048 + ... + 422765773.

It is an arithmetic number, because the mean of its divisors is an integer number (1870205790264).

Almost surely, 2^{21021214515523} is an apocalyptic number.

21021214515523 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21021214515523 is a deficient number, since it is larger than the sum of its proper divisors (1421254967645).

21021214515523 is an equidigital number, since it uses as much as digits as its factorization.

21021214515523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 845481914 (or 845481891 counting only the distinct ones).

The product of its (nonzero) digits is 24000, while the sum is 34.

Adding to 21021214515523 its reverse (32551541212012), we get a palindrome (53572755727535).

The spelling of 21021214515523 in words is "twenty-one trillion, twenty-one billion, two hundred fourteen million, five hundred fifteen thousand, five hundred twenty-three".