990401 has 4 divisors (see below), whose sum is σ = 994992. Its totient is φ = 985812.

The previous prime is 990397. The next prime is 990463. The reversal of 990401 is 104099.

990401 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 104099 = 41 ⋅2539.

It is a cyclic number.

It is not a de Polignac number, because 990401 - 2² = 990397 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (990001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1955 + ... + 2408.

It is an arithmetic number, because the mean of its divisors is an integer number (248748).

2⁹⁹⁰⁴⁰¹ is an apocalyptic number.

It is an amenable number.

990401 is a deficient number, since it is larger than the sum of its proper divisors (4591).

990401 is a wasteful number, since it uses less digits than its factorization.

990401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4590.

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

The square root of 990401 is about 995.1889267873. The cubic root of 990401 is about 99.6790040518.

The spelling of 990401 in words is "nine hundred ninety thousand, four hundred one".