1243664 has 20 divisors (see below), whose sum is σ = 2537040. Its totient is φ = 588960.

The previous prime is 1243663. The next prime is 1243673. The reversal of 1243664 is 4663421.

1243664 = T₈₇ + T₈₈ + ... + T₂₀₀.

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (1243663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1742 + ... + 2349.

It is an arithmetic number, because the mean of its divisors is an integer number (126852).

2^1243664 is an apocalyptic number.

It is an amenable number.

1243664 is an abundant number, since it is smaller than the sum of its proper divisors (1293376).

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

1243664 is a wasteful number, since it uses less digits than its factorization.

1243664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4118 (or 4112 counting only the distinct ones).

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

The square root of 1243664 is about 1115.1968436110. The cubic root of 1243664 is about 107.5394194716.

The spelling of 1243664 in words is "one million, two hundred forty-three thousand, six hundred sixty-four".