1990061 has 4 divisors (see below), whose sum is σ = 1993692. Its totient is φ = 1986432.

The previous prime is 1990039. The next prime is 1990069. The reversal of 1990061 is 1600991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1600991 = 7 ⋅228713.

It can be written as a sum of positive squares in 2 ways, for example, as 504100 + 1485961 = 710^2 + 1219^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1990061 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1990061.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1990069) 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, 806 + ... + 2151.

It is an arithmetic number, because the mean of its divisors is an integer number (498423).

2^1990061 is an apocalyptic number.

It is an amenable number.

1990061 is a deficient number, since it is larger than the sum of its proper divisors (3631).

1990061 is an equidigital number, since it uses as much as digits as its factorization.

1990061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3630.

The product of its (nonzero) digits is 486, while the sum is 26.

The square root of 1990061 is about 1410.6952186777. The cubic root of 1990061 is about 125.7830523886.

The spelling of 1990061 in words is "one million, nine hundred ninety thousand, sixty-one".