1664420 has 12 divisors (see below), whose sum is σ = 3495324. Its totient is φ = 665760.

The previous prime is 1664417. The next prime is 1664431. The reversal of 1664420 is 244661.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 692224 + 972196 = 832^2 + 986^2 .

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41591 + ... + 41630.

It is an arithmetic number, because the mean of its divisors is an integer number (291277).

2^1664420 is an apocalyptic number.

1664420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1664420 is an abundant number, since it is smaller than the sum of its proper divisors (1830904).

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

1664420 is a wasteful number, since it uses less digits than its factorization.

1664420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83230 (or 83228 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 1664420 is about 1290.1240250457. The cubic root of 1664420 is about 118.5098118363.

The spelling of 1664420 in words is "one million, six hundred sixty-four thousand, four hundred twenty".