1997807893 has 2 divisors, whose sum is σ = 1997807894. Its totient is φ = 1997807892.

The previous prime is 1997807849. The next prime is 1997807951. The reversal of 1997807893 is 3987087991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1939697764 + 58110129 = 44042^2 + 7623^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1997807893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1997807813) 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 as a sum of consecutive naturals, namely, 998903946 + 998903947.

It is an arithmetic number, because the mean of its divisors is an integer number (998903947).

Almost surely, 2^1997807893 is an apocalyptic number.

It is an amenable number.

1997807893 is a deficient number, since it is larger than the sum of its proper divisors (1).

1997807893 is an equidigital number, since it uses as much as digits as its factorization.

1997807893 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6858432, while the sum is 61.

The square root of 1997807893 is about 44696.8443293260. The cubic root of 1997807893 is about 1259.4605679908.

The spelling of 1997807893 in words is "one billion, nine hundred ninety-seven million, eight hundred seven thousand, eight hundred ninety-three".