191411561 has 4 divisors (see below), whose sum is σ = 208812624. Its totient is φ = 174010500.

The previous prime is 191411537. The next prime is 191411573. The reversal of 191411561 is 165114191.

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 an emirpimes, since its reverse is a distinct semiprime: 165114191 = 11 ⋅15010381.

It is a cyclic number.

It is not a de Polignac number, because 191411561 - 2¹⁰ = 191410537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (191411501) 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, 8700515 + ... + 8700536.

It is an arithmetic number, because the mean of its divisors is an integer number (52203156).

Almost surely, 2^191411561 is an apocalyptic number.

191411561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

191411561 is a deficient number, since it is larger than the sum of its proper divisors (17401063).

191411561 is a wasteful number, since it uses less digits than its factorization.

191411561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17401062.

The product of its digits is 1080, while the sum is 29.

The square root of 191411561 is about 13835.1567031241. The cubic root of 191411561 is about 576.3098667496.

It can be divided in two parts, 19141 and 1561, that added together give a palindrome (20702).

The spelling of 191411561 in words is "one hundred ninety-one million, four hundred eleven thousand, five hundred sixty-one".