1990966805 has 8 divisors (see below), whose sum is σ = 2389831992. Its totient is φ = 1592325568.

The previous prime is 1990966787. The next prime is 1990966829. The reversal of 1990966805 is 5086690991.

It can be written as a sum of positive squares in 4 ways, for example, as 33258289 + 1957708516 = 5767^2 + 44246^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1990966805 is a prime.

It is a super-2 number, since 2×1990966805² = 7927897637223816050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35762 + ... + 72531.

It is an arithmetic number, because the mean of its divisors is an integer number (298728999).

Almost surely, 2^1990966805 is an apocalyptic number.

It is an amenable number.

1990966805 is a deficient number, since it is larger than the sum of its proper divisors (398865187).

1990966805 is a wasteful number, since it uses less digits than its factorization.

1990966805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111975.

The product of its (nonzero) digits is 1049760, while the sum is 53.

The square root of 1990966805 is about 44620.2510638387. The cubic root of 1990966805 is about 1258.0213348469.

The spelling of 1990966805 in words is "one billion, nine hundred ninety million, nine hundred sixty-six thousand, eight hundred five".