1990565385 has 16 divisors (see below), whose sum is σ = 3252669696. Its totient is φ = 1039046528.

The previous prime is 1990565371. The next prime is 1990565389. The reversal of 1990565385 is 5835650991.

It is a cyclic number.

It is not a de Polignac number, because 1990565385 - 2¹⁸ = 1990303241 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1990565389) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1411044 + ... + 1412453.

It is an arithmetic number, because the mean of its divisors is an integer number (203291856).

Almost surely, 2^1990565385 is an apocalyptic number.

1990565385 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1990565385 is a deficient number, since it is larger than the sum of its proper divisors (1262104311).

1990565385 is a wasteful number, since it uses less digits than its factorization.

1990565385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2823552.

The product of its (nonzero) digits is 1458000, while the sum is 51.

The square root of 1990565385 is about 44615.7526553122. The cubic root of 1990565385 is about 1257.9367814755.

The spelling of 1990565385 in words is "one billion, nine hundred ninety million, five hundred sixty-five thousand, three hundred eighty-five".