1664481 has 36 divisors (see below), whose sum is σ = 2837232. Its totient is φ = 864864.

The previous prime is 1664461. The next prime is 1664501. The reversal of 1664481 is 1844661.

It is an interprime number because it is at equal distance from previous prime (1664461) and next prime (1664501).

It is not a de Polignac number, because 1664481 - 2⁶ = 1664417 is a prime.

It is a super-2 number, since 2×1664481² = 5540993998722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1664431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 24810 + ... + 24876.

It is an arithmetic number, because the mean of its divisors is an integer number (78812).

2^1664481 is an apocalyptic number.

It is an amenable number.

1664481 is a deficient number, since it is larger than the sum of its proper divisors (1172751).

1664481 is a wasteful number, since it uses less digits than its factorization.

1664481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110 (or 90 counting only the distinct ones).

The product of its digits is 4608, while the sum is 30.

The square root of 1664481 is about 1290.1476659670. The cubic root of 1664481 is about 118.5112595899.

It can be divided in two parts, 1664 and 481, that added together give a triangular number (2145 = T₆₅).

The spelling of 1664481 in words is "one million, six hundred sixty-four thousand, four hundred eighty-one".