1990557 has 6 divisors (see below), whose sum is σ = 2875262. Its totient is φ = 1327032.

The previous prime is 1990553. The next prime is 1990559. The reversal of 1990557 is 7550991.

It is a happy number.

1990557 is a `hidden beast` number, since 19 + 90 + 557 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1028196 + 962361 = 1014^2 + 981^2 .

It is not a de Polignac number, because 1990557 - 2² = 1990553 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 (1990553) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 110578 + ... + 110595.

2^1990557 is an apocalyptic number.

It is an amenable number.

1990557 is a deficient number, since it is larger than the sum of its proper divisors (884705).

1990557 is a wasteful number, since it uses less digits than its factorization.

1990557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221179 (or 221176 counting only the distinct ones).

The product of its (nonzero) digits is 14175, while the sum is 36.

The square root of 1990557 is about 1410.8710075694. The cubic root of 1990557 is about 125.7935015174.

The spelling of 1990557 in words is "one million, nine hundred ninety thousand, five hundred fifty-seven".