16181357257 has 4 divisors (see below), whose sum is σ = 17426077060. Its totient is φ = 14936637456.

The previous prime is 16181357243. The next prime is 16181357263. The reversal of 16181357257 is 75275318161.

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 6106015881 + 10075341376 = 78141^2 + 100376^2 .

It is a de Polignac number, because none of the positive numbers 2^k-16181357257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16181357557) 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, 622359882 + ... + 622359907.

It is an arithmetic number, because the mean of its divisors is an integer number (4356519265).

Almost surely, 2^16181357257 is an apocalyptic number.

It is an amenable number.

16181357257 is a deficient number, since it is larger than the sum of its proper divisors (1244719803).

16181357257 is a wasteful number, since it uses less digits than its factorization.

16181357257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1244719802.

The product of its digits is 352800, while the sum is 46.

The spelling of 16181357257 in words is "sixteen billion, one hundred eighty-one million, three hundred fifty-seven thousand, two hundred fifty-seven".