1945688813 has 2 divisors, whose sum is σ = 1945688814. Its totient is φ = 1945688812.

The previous prime is 1945688747. The next prime is 1945688831. The reversal of 1945688813 is 3188865491.

Together with next prime (1945688831) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1256206249 + 689482564 = 35443^2 + 26258^2 .

It is a cyclic number.

It is not a de Polignac number, because 1945688813 - 2¹² = 1945684717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1945688873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 972844406 + 972844407.

It is an arithmetic number, because the mean of its divisors is an integer number (972844407).

Almost surely, 2^1945688813 is an apocalyptic number.

It is an amenable number.

1945688813 is a deficient number, since it is larger than the sum of its proper divisors (1).

1945688813 is an equidigital number, since it uses as much as digits as its factorization.

1945688813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1658880, while the sum is 53.

The square root of 1945688813 is about 44109.9627408593. The cubic root of 1945688813 is about 1248.4115958728.

The spelling of 1945688813 in words is "one billion, nine hundred forty-five million, six hundred eighty-eight thousand, eight hundred thirteen".