1861973 has 2 divisors, whose sum is σ = 1861974. Its totient is φ = 1861972.

The previous prime is 1861961. The next prime is 1861991. The reversal of 1861973 is 3791681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1800964 + 61009 = 1342^2 + 247^2 .

It is an emirp because it is prime and its reverse (3791681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1861973 - 2¹⁶ = 1796437 is a prime.

It is a Sophie Germain prime.

It is an Ulam number.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1861913) 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, 930986 + 930987.

It is an arithmetic number, because the mean of its divisors is an integer number (930987).

2^1861973 is an apocalyptic number.

It is an amenable number.

1861973 is a deficient number, since it is larger than the sum of its proper divisors (1).

1861973 is an equidigital number, since it uses as much as digits as its factorization.

1861973 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 35.

The square root of 1861973 is about 1364.5413148747. The cubic root of 1861973 is about 123.0243633850.

The spelling of 1861973 in words is "one million, eight hundred sixty-one thousand, nine hundred seventy-three".