1664955 has 20 divisors (see below), whose sum is σ = 2985312. Its totient is φ = 887760.

The previous prime is 1664941. The next prime is 1664959. The reversal of 1664955 is 5594661.

1664955 is a `hidden beast` number, since 1 + 6 + 649 + 5 + 5 = 666.

It is not a de Polignac number, because 1664955 - 2¹⁸ = 1402811 is a prime.

1664955 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1664959) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1651 + ... + 2460.

2^1664955 is an apocalyptic number.

1664955 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1664955 is a deficient number, since it is larger than the sum of its proper divisors (1320357).

1664955 is an equidigital number, since it uses as much as digits as its factorization.

1664955 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4128 (or 4119 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 1664955 is about 1290.3313527928. The cubic root of 1664955 is about 118.5225081424.

The spelling of 1664955 in words is "one million, six hundred sixty-four thousand, nine hundred fifty-five".