1664745 has 32 divisors (see below), whose sum is σ = 2851200. Its totient is φ = 827904.

The previous prime is 1664713. The next prime is 1664771. The reversal of 1664745 is 5474661.

1664745 = 89² + 90² + ... + 178².

It is not a de Polignac number, because 1664745 - 2⁵ = 1664713 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18661 + ... + 18749.

It is an arithmetic number, because the mean of its divisors is an integer number (89100).

2^1664745 is an apocalyptic number.

1664745 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1664745 is a deficient number, since it is larger than the sum of its proper divisors (1186455).

1664745 is a wasteful number, since it uses less digits than its factorization.

1664745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169.

The product of its digits is 20160, while the sum is 33.

The square root of 1664745 is about 1290.2499757799. The cubic root of 1664745 is about 118.5175248699.

The spelling of 1664745 in words is "one million, six hundred sixty-four thousand, seven hundred forty-five".