191464661 has 4 divisors (see below), whose sum is σ = 191493324. Its totient is φ = 191436000.

The previous prime is 191464657. The next prime is 191464697. The reversal of 191464661 is 166464191.

191464661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 166464191 = 977 ⋅170383.

It can be written as a sum of positive squares in 2 ways, for example, as 159542161 + 31922500 = 12631^2 + 5650^2 .

It is a cyclic number.

It is not a de Polignac number, because 191464661 - 2² = 191464657 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 (191464631) 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, 1571 + ... + 19631.

It is an arithmetic number, because the mean of its divisors is an integer number (47873331).

Almost surely, 2^191464661 is an apocalyptic number.

It is an amenable number.

191464661 is a deficient number, since it is larger than the sum of its proper divisors (28663).

191464661 is a wasteful number, since it uses less digits than its factorization.

191464661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28662.

The product of its digits is 31104, while the sum is 38.

The square root of 191464661 is about 13837.0755942143. The cubic root of 191464661 is about 576.3631537166.

The spelling of 191464661 in words is "one hundred ninety-one million, four hundred sixty-four thousand, six hundred sixty-one".