1642703809 has 2 divisors, whose sum is σ = 1642703810. Its totient is φ = 1642703808.

The previous prime is 1642703771. The next prime is 1642703819. The reversal of 1642703809 is 9083072461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1389798400 + 252905409 = 37280^2 + 15903^2 .

It is a cyclic number.

It is not a de Polignac number, because 1642703809 - 2⁹ = 1642703297 is a prime.

It is not a weakly prime, because it can be changed into another prime (1642703819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 821351904 + 821351905.

It is an arithmetic number, because the mean of its divisors is an integer number (821351905).

Almost surely, 2^1642703809 is an apocalyptic number.

It is an amenable number.

1642703809 is a deficient number, since it is larger than the sum of its proper divisors (1).

1642703809 is an equidigital number, since it uses as much as digits as its factorization.

1642703809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 1642703809 is about 40530.2826168286. The cubic root of 1642703809 is about 1179.9214275462.

The spelling of 1642703809 in words is "one billion, six hundred forty-two million, seven hundred three thousand, eight hundred nine".