194391561 has 64 divisors (see below), whose sum is σ = 337784832. Its totient is φ = 96636672.

The previous prime is 194391559. The next prime is 194391563. The reversal of 194391561 is 165193491.

It is an interprime number because it is at equal distance from previous prime (194391559) and next prime (194391563).

It is not a de Polignac number, because 194391561 - 2¹ = 194391559 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (194391563) 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 63 ways as a sum of consecutive naturals, for example, 520971 + ... + 521343.

It is an arithmetic number, because the mean of its divisors is an integer number (5277888).

Almost surely, 2^194391561 is an apocalyptic number.

It is an amenable number.

194391561 is a deficient number, since it is larger than the sum of its proper divisors (143393271).

194391561 is a wasteful number, since it uses less digits than its factorization.

194391561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 502.

The product of its digits is 29160, while the sum is 39.

The square root of 194391561 is about 13942.4374124469. The cubic root of 194391561 is about 579.2852481679.

The spelling of 194391561 in words is "one hundred ninety-four million, three hundred ninety-one thousand, five hundred sixty-one".