16500051421 has 16 divisors (see below), whose sum is σ = 20001231360. Its totient is φ = 13296245040.

The previous prime is 16500051361. The next prime is 16500051427. The reversal of 16500051421 is 12415000561.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 16500051421 - 2¹⁵ = 16500018653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16500051427) 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, 456091 + ... + 490936.

It is an arithmetic number, because the mean of its divisors is an integer number (1250076960).

Almost surely, 2^16500051421 is an apocalyptic number.

It is an amenable number.

16500051421 is a deficient number, since it is larger than the sum of its proper divisors (3501179939).

16500051421 is a wasteful number, since it uses less digits than its factorization.

16500051421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 947184.

The product of its (nonzero) digits is 1200, while the sum is 25.

Adding to 16500051421 its reverse (12415000561), we get a palindrome (28915051982).

The spelling of 16500051421 in words is "sixteen billion, five hundred million, fifty-one thousand, four hundred twenty-one".