16725721457 has 4 divisors (see below), whose sum is σ = 16731808500. Its totient is φ = 16719634416.

The previous prime is 16725721423. The next prime is 16725721469. The reversal of 16725721457 is 75412752761.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75412752761 = 1999 ⋅37725239.

It can be written as a sum of positive squares in 2 ways, for example, as 4760862001 + 11964859456 = 68999^2 + 109384^2 .

It is a cyclic number.

It is not a de Polignac number, because 16725721457 - 2⁶ = 16725721393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16725721487) 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, 3039398 + ... + 3044895.

It is an arithmetic number, because the mean of its divisors is an integer number (4182952125).

Almost surely, 2^16725721457 is an apocalyptic number.

It is an amenable number.

16725721457 is a deficient number, since it is larger than the sum of its proper divisors (6087043).

16725721457 is an equidigital number, since it uses as much as digits as its factorization.

16725721457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6087042.

The product of its digits is 823200, while the sum is 47.

The spelling of 16725721457 in words is "sixteen billion, seven hundred twenty-five million, seven hundred twenty-one thousand, four hundred fifty-seven".