1643264 has 54 divisors (see below), whose sum is σ = 3844764. Its totient is φ = 698880.

The previous prime is 1643251. The next prime is 1643269. The reversal of 1643264 is 4623461.

It is a d-powerful number, because it can be written as 1 + 6³ + 4 + 3¹³ + 2¹¹ + 6⁶ + 4² .

It is not an unprimeable number, because it can be changed into a prime (1643269) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12479 + ... + 12609.

2^1643264 is an apocalyptic number.

1643264 is a gapful number since it is divisible by the number (14) 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 1643264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1922382).

1643264 is an abundant number, since it is smaller than the sum of its proper divisors (2201500).

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

1643264 is an equidigital number, since it uses as much as digits as its factorization.

1643264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161 (or 140 counting only the distinct ones).

The product of its digits is 3456, while the sum is 26.

The square root of 1643264 is about 1281.8985919331. The cubic root of 1643264 is about 118.0055536982.

It can be divided in two parts, 16 and 43264, that multiplied together give a square (692224 = 832²).

The spelling of 1643264 in words is "one million, six hundred forty-three thousand, two hundred sixty-four".