161898263 has 4 divisors (see below), whose sum is σ = 162543528. Its totient is φ = 161253000.

The previous prime is 161898251. The next prime is 161898281. The reversal of 161898263 is 362898161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 362898161 = 83 ⋅4372267.

It is a cyclic number.

It is not a de Polignac number, because 161898263 - 2¹² = 161894167 is a prime.

It is a super-2 number, since 2×161898263² = 52422095124834338, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161838263) 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, 322256 + ... + 322757.

It is an arithmetic number, because the mean of its divisors is an integer number (40635882).

Almost surely, 2^161898263 is an apocalyptic number.

161898263 is a deficient number, since it is larger than the sum of its proper divisors (645265).

161898263 is an equidigital number, since it uses as much as digits as its factorization.

161898263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645264.

The product of its digits is 124416, while the sum is 44.

The square root of 161898263 is about 12723.9248268763. The cubic root of 161898263 is about 545.0220376578.

The spelling of 161898263 in words is "one hundred sixty-one million, eight hundred ninety-eight thousand, two hundred sixty-three".