1645401 has 8 divisors (see below), whose sum is σ = 2201824. Its totient is φ = 1092960.

The previous prime is 1645367. The next prime is 1645409. The reversal of 1645401 is 1045461.

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

It is not a de Polignac number, because 1645401 - 2⁶ = 1645337 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1645409) 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, 165 + ... + 1821.

It is an arithmetic number, because the mean of its divisors is an integer number (275228).

2^1645401 is an apocalyptic number.

It is an amenable number.

1645401 is a deficient number, since it is larger than the sum of its proper divisors (556423).

1645401 is a wasteful number, since it uses less digits than its factorization.

1645401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1991.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 1645401 is about 1282.7318503881. The cubic root of 1645401 is about 118.0566853953.

It can be divided in two parts, 164 and 5401, that added together give a triangular number (5565 = T₁₀₅).

The spelling of 1645401 in words is "one million, six hundred forty-five thousand, four hundred one".