16725043721 has 6 divisors (see below), whose sum is σ = 17651639322. Its totient is φ = 15844777920.

The previous prime is 16725043697. The next prime is 16725043823. The reversal of 16725043721 is 12734052761.

It can be written as a sum of positive squares in only one way, i.e., 15163213321 + 1561830400 = 123139^2 + 39520^2 .

It is not a de Polignac number, because 16725043721 - 2¹⁴ = 16725027337 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16725040721) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 23164520 + ... + 23165241.

It is an arithmetic number, because the mean of its divisors is an integer number (2941939887).

Almost surely, 2^16725043721 is an apocalyptic number.

It is an amenable number.

16725043721 is a deficient number, since it is larger than the sum of its proper divisors (926595601).

16725043721 is an equidigital number, since it uses as much as digits as its factorization.

16725043721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46329799 (or 46329780 counting only the distinct ones).

The product of its (nonzero) digits is 70560, while the sum is 38.

The spelling of 16725043721 in words is "sixteen billion, seven hundred twenty-five million, forty-three thousand, seven hundred twenty-one".