161216663257 has 12 divisors (see below), whose sum is σ = 175536408684. Its totient is φ = 147993168960.

The previous prime is 161216663249. The next prime is 161216663357. The reversal of 161216663257 is 752366612161.

It can be written as a sum of positive squares in 6 ways, for example, as 79431530896 + 81785132361 = 281836^2 + 285981^2 .

It is not a de Polignac number, because 161216663257 - 2³ = 161216663249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161216663357) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2604618 + ... + 2665795.

It is an arithmetic number, because the mean of its divisors is an integer number (14628034057).

Almost surely, 2^161216663257 is an apocalyptic number.

It is an amenable number.

161216663257 is a deficient number, since it is larger than the sum of its proper divisors (14319745427).

161216663257 is a wasteful number, since it uses less digits than its factorization.

161216663257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5270620 (or 5270607 counting only the distinct ones).

The product of its digits is 544320, while the sum is 46.

The spelling of 161216663257 in words is "one hundred sixty-one billion, two hundred sixteen million, six hundred sixty-three thousand, two hundred fifty-seven".