1990400 has 54 divisors (see below), whose sum is σ = 4942392. Its totient is φ = 793600.

The previous prime is 1990381. The next prime is 1990433. The reversal of 1990400 is 40991.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6245 + ... + 6555.

2^1990400 is an apocalyptic number.

1990400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1990400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2471196).

1990400 is an abundant number, since it is smaller than the sum of its proper divisors (2951992).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1990400 is an equidigital number, since it uses as much as digits as its factorization.

1990400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 337 (or 318 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 1990400 is about 1410.8153670839. The cubic root of 1990400 is about 125.7901942188.

The spelling of 1990400 in words is "one million, nine hundred ninety thousand, four hundred".