1990395305 has 4 divisors (see below), whose sum is σ = 2388474372. Its totient is φ = 1592316240.

The previous prime is 1990395287. The next prime is 1990395347. The reversal of 1990395305 is 5035930991.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1465664656 + 524730649 = 38284^2 + 22907^2 .

It is not a de Polignac number, because 1990395305 - 2²⁸ = 1721959849 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 199039526 + ... + 199039535.

It is an arithmetic number, because the mean of its divisors is an integer number (597118593).

Almost surely, 2^1990395305 is an apocalyptic number.

It is an amenable number.

1990395305 is a deficient number, since it is larger than the sum of its proper divisors (398079067).

1990395305 is an equidigital number, since it uses as much as digits as its factorization.

1990395305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 398079066.

The product of its (nonzero) digits is 164025, while the sum is 44.

The square root of 1990395305 is about 44613.8465613536. The cubic root of 1990395305 is about 1257.9009531320.

The spelling of 1990395305 in words is "one billion, nine hundred ninety million, three hundred ninety-five thousand, three hundred five".