21213543231503 has 16 divisors (see below), whose sum is σ = 24763304315904. Its totient is φ = 17793702876960.

The previous prime is 21213543231497. The next prime is 21213543231577. The reversal of 21213543231503 is 30513234531212.

It is a cyclic number.

It is not a de Polignac number, because 21213543231503 - 2²² = 21213539037199 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213543231703) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2073833 + ... + 6835778.

It is an arithmetic number, because the mean of its divisors is an integer number (1547706519744).

Almost surely, 2^{21213543231503} is an apocalyptic number.

21213543231503 is a deficient number, since it is larger than the sum of its proper divisors (3549761084401).

21213543231503 is an equidigital number, since it uses as much as digits as its factorization.

21213543231503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8916902.

The product of its (nonzero) digits is 64800, while the sum is 35.

Adding to 21213543231503 its reverse (30513234531212), we get a palindrome (51726777762715).

The spelling of 21213543231503 in words is "twenty-one trillion, two hundred thirteen billion, five hundred forty-three million, two hundred thirty-one thousand, five hundred three".