1990537 has 4 divisors (see below), whose sum is σ = 2011156. Its totient is φ = 1969920.

The previous prime is 1990529. The next prime is 1990543. The reversal of 1990537 is 7350991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7350991 = 1597 ⋅4603.

It can be written as a sum of positive squares in 2 ways, for example, as 1089936 + 900601 = 1044^2 + 949^2 .

It is a cyclic number.

It is not a de Polignac number, because 1990537 - 2³ = 1990529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1990507) 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 3 ways as a sum of consecutive naturals, for example, 10164 + ... + 10357.

It is an arithmetic number, because the mean of its divisors is an integer number (502789).

2^1990537 is an apocalyptic number.

It is an amenable number.

1990537 is a deficient number, since it is larger than the sum of its proper divisors (20619).

1990537 is an equidigital number, since it uses as much as digits as its factorization.

1990537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20618.

The product of its (nonzero) digits is 8505, while the sum is 34.

The square root of 1990537 is about 1410.8639197315. The cubic root of 1990537 is about 125.7930802152.

The spelling of 1990537 in words is "one million, nine hundred ninety thousand, five hundred thirty-seven".