1990390 has 8 divisors (see below), whose sum is σ = 3582720. Its totient is φ = 796152.

The previous prime is 1990381. The next prime is 1990433. The reversal of 1990390 is 930991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99510 + ... + 99529.

It is an arithmetic number, because the mean of its divisors is an integer number (447840).

2^1990390 is an apocalyptic number.

1990390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1990390 is a deficient number, since it is larger than the sum of its proper divisors (1592330).

1990390 is a wasteful number, since it uses less digits than its factorization.

1990390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199046.

The product of its (nonzero) digits is 2187, while the sum is 31.

The square root of 1990390 is about 1410.8118230296. The cubic root of 1990390 is about 125.7899835570.

It can be divided in two parts, 19 and 90390, that added together give a palindrome (90409).

The spelling of 1990390 in words is "one million, nine hundred ninety thousand, three hundred ninety".