1663601 has 4 divisors (see below), whose sum is σ = 1687104. Its totient is φ = 1640100.

The previous prime is 1663589. The next prime is 1663609. The reversal of 1663601 is 1063661.

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.

It is not a de Polignac number, because 1663601 - 2⁶ = 1663537 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663609) 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, 11645 + ... + 11786.

It is an arithmetic number, because the mean of its divisors is an integer number (421776).

2^1663601 is an apocalyptic number.

It is an amenable number.

1663601 is a deficient number, since it is larger than the sum of its proper divisors (23503).

1663601 is an equidigital number, since it uses as much as digits as its factorization.

1663601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23502.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 1663601 is about 1289.8065746460. The cubic root of 1663601 is about 118.4903705374.

The spelling of 1663601 in words is "one million, six hundred sixty-three thousand, six hundred one".