1604400665 has 8 divisors (see below), whose sum is σ = 2200320960. Its totient is φ = 1100160432.

The previous prime is 1604400659. The next prime is 1604400667. The reversal of 1604400665 is 5660044061.

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

It is not a de Polignac number, because 1604400665 - 2²⁰ = 1603352089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1604400667) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22919975 + ... + 22920044.

It is an arithmetic number, because the mean of its divisors is an integer number (275040120).

Almost surely, 2^1604400665 is an apocalyptic number.

It is an amenable number.

1604400665 is a deficient number, since it is larger than the sum of its proper divisors (595920295).

1604400665 is an equidigital number, since it uses as much as digits as its factorization.

1604400665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45840031.

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 1604400665 is about 40054.9705404960. The cubic root of 1604400665 is about 1170.6784155693.

The spelling of 1604400665 in words is "one billion, six hundred four million, four hundred thousand, six hundred sixty-five".