13503432321 has 20 divisors (see below), whose sum is σ = 20822500864. Its totient is φ = 8711890200.

The previous prime is 13503432307. The next prime is 13503432329. The reversal of 13503432321 is 12323430531.

It is not a de Polignac number, because 13503432321 - 2⁵ = 13503432289 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13503432329) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2686345 + ... + 2691366.

Almost surely, 2^13503432321 is an apocalyptic number.

It is an amenable number.

13503432321 is a deficient number, since it is larger than the sum of its proper divisors (7319068543).

13503432321 is an equidigital number, since it uses as much as digits as its factorization.

13503432321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5377754 (or 5377745 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 27.

Adding to 13503432321 its reverse (12323430531), we get a palindrome (25826862852).

The spelling of 13503432321 in words is "thirteen billion, five hundred three million, four hundred thirty-two thousand, three hundred twenty-one".