21531352503143 has 6 divisors (see below), whose sum is σ = 25046675360856. Its totient is φ = 18455445002652.

The previous prime is 21531352503137. The next prime is 21531352503173. The reversal of 21531352503143 is 34130525313512.

It is not a de Polignac number, because 21531352503143 - 2³⁴ = 21514172633959 is a prime.

It is a super-2 number, since 2×21531352503143² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21531352503097 and 21531352503106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21531352503103) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 219707678555 + ... + 219707678652.

It is an arithmetic number, because the mean of its divisors is an integer number (4174445893476).

Almost surely, 2^{21531352503143} is an apocalyptic number.

21531352503143 is a deficient number, since it is larger than the sum of its proper divisors (3515322857713).

21531352503143 is an equidigital number, since it uses as much as digits as its factorization.

21531352503143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439415357221 (or 439415357214 counting only the distinct ones).

The product of its (nonzero) digits is 162000, while the sum is 38.

Adding to 21531352503143 its reverse (34130525313512), we get a palindrome (55661877816655).

The spelling of 21531352503143 in words is "twenty-one trillion, five hundred thirty-one billion, three hundred fifty-two million, five hundred three thousand, one hundred forty-three".