1645997 has 8 divisors (see below), whose sum is σ = 1705440. Its totient is φ = 1587600.

The previous prime is 1645979. The next prime is 1645999. The reversal of 1645997 is 7995461.

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 1645997 - 2⁶ = 1645933 is a prime.

It is a super-2 number, since 2×1645997² = 5418612248018, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645999) 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, 4154 + ... + 4532.

It is an arithmetic number, because the mean of its divisors is an integer number (213180).

2^1645997 is an apocalyptic number.

It is an amenable number.

1645997 is a deficient number, since it is larger than the sum of its proper divisors (59443).

1645997 is a wasteful number, since it uses less digits than its factorization.

1645997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 523.

The product of its digits is 68040, while the sum is 41.

The square root of 1645997 is about 1282.9641460306. The cubic root of 1645997 is about 118.0709379069.

The spelling of 1645997 in words is "one million, six hundred forty-five thousand, nine hundred ninety-seven".