16501123420 has 96 divisors (see below), whose sum is σ = 37547596800. Its totient is φ = 6072019200.

The previous prime is 16501123399. The next prime is 16501123447. The reversal of 16501123420 is 2432110561.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1826715 + ... + 1835725.

It is an arithmetic number, because the mean of its divisors is an integer number (391120800).

Almost surely, 2^16501123420 is an apocalyptic number.

16501123420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16501123420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18773798400).

16501123420 is an abundant number, since it is smaller than the sum of its proper divisors (21046473380).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16501123420 is a wasteful number, since it uses less digits than its factorization.

16501123420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9179 (or 9177 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

Adding to 16501123420 its reverse (2432110561), we get a palindrome (18933233981).

The spelling of 16501123420 in words is "sixteen billion, five hundred one million, one hundred twenty-three thousand, four hundred twenty".