161902617893 has 4 divisors (see below), whose sum is σ = 162597479148. Its totient is φ = 161207756640.

The previous prime is 161902617881. The next prime is 161902617907. The reversal of 161902617893 is 398716209161.

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 38942286244 + 122960331649 = 197338^2 + 350657^2 .

It is a cyclic number.

It is not a de Polignac number, because 161902617893 - 2¹⁸ = 161902355749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161902617193) 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, 347430278 + ... + 347430743.

It is an arithmetic number, because the mean of its divisors is an integer number (40649369787).

Almost surely, 2^161902617893 is an apocalyptic number.

It is an amenable number.

161902617893 is a deficient number, since it is larger than the sum of its proper divisors (694861255).

161902617893 is an equidigital number, since it uses as much as digits as its factorization.

161902617893 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 694861254.

The product of its (nonzero) digits is 979776, while the sum is 53.

The spelling of 161902617893 in words is "one hundred sixty-one billion, nine hundred two million, six hundred seventeen thousand, eight hundred ninety-three".