1990690 has 16 divisors (see below), whose sum is σ = 3859128. Its totient is φ = 734976.

The previous prime is 1990679. The next prime is 1990691. The reversal of 1990690 is 960991.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 499849 + 1490841 = 707^2 + 1221^2 .

It is a super-2 number, since 2×1990690² = 7925693352200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1990691) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7527 + ... + 7786.

2^1990690 is an apocalyptic number.

1990690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1990690 is a deficient number, since it is larger than the sum of its proper divisors (1868438).

1990690 is a wasteful number, since it uses less digits than its factorization.

1990690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15333.

The product of its (nonzero) digits is 4374, while the sum is 34.

The square root of 1990690 is about 1410.9181407863. The cubic root of 1990690 is about 125.7963031056.

It can be divided in two parts, 19 and 90690, that added together give a palindrome (90709).

The spelling of 1990690 in words is "one million, nine hundred ninety thousand, six hundred ninety".