1620401 has 8 divisors (see below), whose sum is σ = 1688064. Its totient is φ = 1553760.

The previous prime is 1620391. The next prime is 1620403. The reversal of 1620401 is 1040261.

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

It is a cyclic number.

It is not a de Polignac number, because 1620401 - 2⁶ = 1620337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1620403) 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, 5021 + ... + 5333.

It is an arithmetic number, because the mean of its divisors is an integer number (211008).

2^1620401 is an apocalyptic number.

It is an amenable number.

1620401 is a deficient number, since it is larger than the sum of its proper divisors (67663).

1620401 is a wasteful number, since it uses less digits than its factorization.

1620401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 511.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 1620401 is about 1272.9497240661. The cubic root of 1620401 is about 117.4557189413.

Adding to 1620401 its reverse (1040261), we get a palindrome (2660662).

The spelling of 1620401 in words is "one million, six hundred twenty thousand, four hundred one".