194250781 has 2 divisors, whose sum is σ = 194250782. Its totient is φ = 194250780.

The previous prime is 194250773. The next prime is 194250799. The reversal of 194250781 is 187052491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 164711556 + 29539225 = 12834^2 + 5435^2 .

It is a cyclic number.

It is not a de Polignac number, because 194250781 - 2³ = 194250773 is a prime.

It is a super-2 number, since 2×194250781² = 75466731838219922, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 194250781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (194250731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97125390 + 97125391.

It is an arithmetic number, because the mean of its divisors is an integer number (97125391).

Almost surely, 2^194250781 is an apocalyptic number.

It is an amenable number.

194250781 is a deficient number, since it is larger than the sum of its proper divisors (1).

194250781 is an equidigital number, since it uses as much as digits as its factorization.

194250781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20160, while the sum is 37.

The square root of 194250781 is about 13937.3878829571. The cubic root of 194250781 is about 579.1453733167.

The spelling of 194250781 in words is "one hundred ninety-four million, two hundred fifty thousand, seven hundred eighty-one".