1940889817 has 2 divisors, whose sum is σ = 1940889818. Its totient is φ = 1940889816.

The previous prime is 1940889809. The next prime is 1940889851. The reversal of 1940889817 is 7189880491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1918790416 + 22099401 = 43804^2 + 4701^2 .

It is a cyclic number.

It is not a de Polignac number, because 1940889817 - 2³ = 1940889809 is a prime.

It is not a weakly prime, because it can be changed into another prime (1940889217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 970444908 + 970444909.

It is an arithmetic number, because the mean of its divisors is an integer number (970444909).

Almost surely, 2^1940889817 is an apocalyptic number.

It is an amenable number.

1940889817 is a deficient number, since it is larger than the sum of its proper divisors (1).

1940889817 is an equidigital number, since it uses as much as digits as its factorization.

1940889817 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1161216, while the sum is 55.

The square root of 1940889817 is about 44055.5310602426. The cubic root of 1940889817 is about 1247.3843581786.

The spelling of 1940889817 in words is "one billion, nine hundred forty million, eight hundred eighty-nine thousand, eight hundred seventeen".