16198390261 has 4 divisors (see below), whose sum is σ = 16420286092. Its totient is φ = 15976494432.

The previous prime is 16198390259. The next prime is 16198390267. The reversal of 16198390261 is 16209389161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16209389161 = 7 ⋅2315627023.

It can be written as a sum of positive squares in 2 ways, for example, as 4592637361 + 11605752900 = 67769^2 + 107730^2 .

It is a cyclic number.

It is not a de Polignac number, because 16198390261 - 2¹ = 16198390259 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 (16198390267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110947806 + ... + 110947951.

It is an arithmetic number, because the mean of its divisors is an integer number (4105071523).

Almost surely, 2^16198390261 is an apocalyptic number.

It is an amenable number.

16198390261 is a deficient number, since it is larger than the sum of its proper divisors (221895831).

16198390261 is an equidigital number, since it uses as much as digits as its factorization.

16198390261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221895830.

The product of its (nonzero) digits is 139968, while the sum is 46.

The spelling of 16198390261 in words is "sixteen billion, one hundred ninety-eight million, three hundred ninety thousand, two hundred sixty-one".