16531233420403 has 4 divisors (see below), whose sum is σ = 17802866760448. Its totient is φ = 15259600080360.

The previous prime is 16531233420367. The next prime is 16531233420439. The reversal of 16531233420403 is 30402433213561.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (16531233420367) and next prime (16531233420439).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16531233420403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16531233420203) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 635816670003 + ... + 635816670028.

It is an arithmetic number, because the mean of its divisors is an integer number (4450716690112).

Almost surely, 2^{16531233420403} is an apocalyptic number.

16531233420403 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

16531233420403 is a deficient number, since it is larger than the sum of its proper divisors (1271633340045).

16531233420403 is a wasteful number, since it uses less digits than its factorization.

16531233420403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1271633340044.

The product of its (nonzero) digits is 155520, while the sum is 37.

Adding to 16531233420403 its reverse (30402433213561), we get a palindrome (46933666633964).

The spelling of 16531233420403 in words is "sixteen trillion, five hundred thirty-one billion, two hundred thirty-three million, four hundred twenty thousand, four hundred three".