16545721051251 has 24 divisors (see below), whose sum is σ = 27322903156224. Its totient is φ = 9451467471600.

The previous prime is 16545721051241. The next prime is 16545721051261. The reversal of 16545721051251 is 15215012754561.

16545721051251 is a `hidden beast` number, since 1 + 6 + 5 + 4 + 5 + 72 + 10 + 512 + 51 = 666.

It is an interprime number because it is at equal distance from previous prime (16545721051241) and next prime (16545721051261).

It is not a de Polignac number, because 16545721051251 - 2¹¹ = 16545721049203 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16545721051197 and 16545721051206.

It is not an unprimeable number, because it can be changed into a prime (16545721051201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 44679025 + ... + 45047826.

It is an arithmetic number, because the mean of its divisors is an integer number (1138454298176).

Almost surely, 2^{16545721051251} is an apocalyptic number.

16545721051251 is a deficient number, since it is larger than the sum of its proper divisors (10777182104973).

16545721051251 is a wasteful number, since it uses less digits than its factorization.

16545721051251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89729791 (or 89729788 counting only the distinct ones).

The product of its (nonzero) digits is 420000, while the sum is 45.

The spelling of 16545721051251 in words is "sixteen trillion, five hundred forty-five billion, seven hundred twenty-one million, fifty-one thousand, two hundred fifty-one".