1990564 has 24 divisors (see below), whose sum is σ = 3748248. Its totient is φ = 921600.

The previous prime is 1990559. The next prime is 1990577. The reversal of 1990564 is 4650991.

It can be written as a sum of positive squares in 4 ways, for example, as 1254400 + 736164 = 1120^2 + 858^2 .

It is a Harshad number since it is a multiple of its sum of digits (34).

It is an Ulam number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4764 + ... + 5164.

It is an arithmetic number, because the mean of its divisors is an integer number (156177).

2^1990564 is an apocalyptic number.

It is an amenable number.

1990564 is a deficient number, since it is larger than the sum of its proper divisors (1757684).

1990564 is a wasteful number, since it uses less digits than its factorization.

1990564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 495 (or 493 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 1990564 is about 1410.8734883043. The cubic root of 1990564 is about 125.7936489725.

The spelling of 1990564 in words is "one million, nine hundred ninety thousand, five hundred sixty-four".