1990517 has 4 divisors (see below), whose sum is σ = 1994496. Its totient is φ = 1986540.

The previous prime is 1990507. The next prime is 1990523. The reversal of 1990517 is 7150991.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7150991 = 479 ⋅14929.

It is a cyclic number.

It is not a de Polignac number, because 1990517 - 2⁶ = 1990453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1990507) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1109 + ... + 2282.

It is an arithmetic number, because the mean of its divisors is an integer number (498624).

2^1990517 is an apocalyptic number.

It is an amenable number.

1990517 is a deficient number, since it is larger than the sum of its proper divisors (3979).

1990517 is an equidigital number, since it uses as much as digits as its factorization.

1990517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3978.

The product of its (nonzero) digits is 2835, while the sum is 32.

The square root of 1990517 is about 1410.8568318579. The cubic root of 1990517 is about 125.7926589101.

The spelling of 1990517 in words is "one million, nine hundred ninety thousand, five hundred seventeen".