16720516457 has 4 divisors (see below), whose sum is σ = 17297086020. Its totient is φ = 16143946896.

The previous prime is 16720516429. The next prime is 16720516459. The reversal of 16720516457 is 75461502761.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9239823376 + 7480693081 = 96124^2 + 86491^2 .

It is not a de Polignac number, because 16720516457 - 2¹⁰ = 16720515433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16720516459) 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, 288284738 + ... + 288284795.

It is an arithmetic number, because the mean of its divisors is an integer number (4324271505).

Almost surely, 2^16720516457 is an apocalyptic number.

It is an amenable number.

16720516457 is a deficient number, since it is larger than the sum of its proper divisors (576569563).

16720516457 is an equidigital number, since it uses as much as digits as its factorization.

16720516457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 576569562.

The product of its (nonzero) digits is 352800, while the sum is 44.

The spelling of 16720516457 in words is "sixteen billion, seven hundred twenty million, five hundred sixteen thousand, four hundred fifty-seven".