1990401 has 8 divisors (see below), whose sum is σ = 3033024. Its totient is φ = 1137360.

The previous prime is 1990381. The next prime is 1990433. The reversal of 1990401 is 1040991.

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

It is not a de Polignac number, because 1990401 - 2⁶ = 1990337 is a prime.

It is a super-2 number, since 2×1990401² = 7923392281602, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1990441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47370 + ... + 47411.

It is an arithmetic number, because the mean of its divisors is an integer number (379128).

2^1990401 is an apocalyptic number.

It is an amenable number.

1990401 is a deficient number, since it is larger than the sum of its proper divisors (1042623).

1990401 is an equidigital number, since it uses as much as digits as its factorization.

1990401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94791.

The product of its (nonzero) digits is 324, while the sum is 24.

The square root of 1990401 is about 1410.8157214888. The cubic root of 1990401 is about 125.7902152850.

The spelling of 1990401 in words is "one million, nine hundred ninety thousand, four hundred one".