1664187 has 12 divisors (see below), whose sum is σ = 2581416. Its totient is φ = 950880.

The previous prime is 1664123. The next prime is 1664227. The reversal of 1664187 is 7814661.

It is a happy number.

It is not a de Polignac number, because 1664187 - 2⁶ = 1664123 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1664287) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5514 + ... + 5807.

It is an arithmetic number, because the mean of its divisors is an integer number (215118).

2^1664187 is an apocalyptic number.

1664187 is a deficient number, since it is larger than the sum of its proper divisors (917229).

1664187 is a wasteful number, since it uses less digits than its factorization.

1664187 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11338 (or 11331 counting only the distinct ones).

The product of its digits is 8064, while the sum is 33.

The square root of 1664187 is about 1290.0337204895. The cubic root of 1664187 is about 118.5042815665.

The spelling of 1664187 in words is "one million, six hundred sixty-four thousand, one hundred eighty-seven".