1990545 has 16 divisors (see below), whose sum is σ = 3212352. Its totient is φ = 1052480.

The previous prime is 1990543. The next prime is 1990553. The reversal of 1990545 is 5450991.

It is not a de Polignac number, because 1990545 - 2¹ = 1990543 is a prime.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (1990543) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 1459 + ... + 2471.

It is an arithmetic number, because the mean of its divisors is an integer number (200772).

2^1990545 is an apocalyptic number.

1990545 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1990545 is a deficient number, since it is larger than the sum of its proper divisors (1221807).

1990545 is a wasteful number, since it uses less digits than its factorization.

1990545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1152.

The product of its (nonzero) digits is 8100, while the sum is 33.

The square root of 1990545 is about 1410.8667548709. The cubic root of 1990545 is about 125.7932487364.

The spelling of 1990545 in words is "one million, nine hundred ninety thousand, five hundred forty-five".