19117961 has 4 divisors (see below), whose sum is σ = 19126800. Its totient is φ = 19109124.

The previous prime is 19117951. The next prime is 19117963. The reversal of 19117961 is 16971191.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 16971191 = 109 ⋅155699.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19117961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19117963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1250 + ... + 6308.

It is an arithmetic number, because the mean of its divisors is an integer number (4781700).

Almost surely, 2^19117961 is an apocalyptic number.

It is an amenable number.

19117961 is a deficient number, since it is larger than the sum of its proper divisors (8839).

19117961 is an equidigital number, since it uses as much as digits as its factorization.

19117961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8838.

The product of its digits is 3402, while the sum is 35.

The square root of 19117961 is about 4372.4090613757. The cubic root of 19117961 is about 267.3912493568.

The spelling of 19117961 in words is "nineteen million, one hundred seventeen thousand, nine hundred sixty-one".