1664040 has 96 divisors (see below), whose sum is σ = 5827680. Its totient is φ = 379008.

The previous prime is 1664021. The next prime is 1664053. The reversal of 1664040 is 404661.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 1663998 and 1664016.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5739 + ... + 6021.

It is an arithmetic number, because the mean of its divisors is an integer number (60705).

2^1664040 is an apocalyptic number.

1664040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1664040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2913840).

1664040 is an abundant number, since it is smaller than the sum of its proper divisors (4163640).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1664040 is a wasteful number, since it uses less digits than its factorization.

1664040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311 (or 300 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 1664040 is about 1289.9767439764. The cubic root of 1664040 is about 118.5007922467.

The spelling of 1664040 in words is "one million, six hundred sixty-four thousand, forty".