1604391 has 8 divisors (see below), whose sum is σ = 2156544. Its totient is φ = 1060920.

The previous prime is 1604381. The next prime is 1604399. The reversal of 1604391 is 1934061.

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

It is not a de Polignac number, because 1604391 - 2⁵ = 1604359 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1604399) 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, 1725 + ... + 2486.

It is an arithmetic number, because the mean of its divisors is an integer number (269568).

2^1604391 is an apocalyptic number.

1604391 is a deficient number, since it is larger than the sum of its proper divisors (552153).

1604391 is a wasteful number, since it uses less digits than its factorization.

1604391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4341.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 1604391 is about 1266.6455699998. The cubic root of 1604391 is about 117.0676064820.

The spelling of 1604391 in words is "one million, six hundred four thousand, three hundred ninety-one".