1993644 has 36 divisors (see below), whose sum is σ = 5110560. Its totient is φ = 655200.

The previous prime is 1993643. The next prime is 1993657. The reversal of 1993644 is 4463991.

1993644 = T₁₈₄ + T₁₈₅ + ... + T₂₆₂.

1993644 is a `hidden beast` number, since 1 + 9 + 9 + 3 + 644 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 1993599 and 1993608.

It is not an unprimeable number, because it can be changed into a prime (1993643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2494 + ... + 3194.

It is an arithmetic number, because the mean of its divisors is an integer number (141960).

2^1993644 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1993644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2555280).

1993644 is an abundant number, since it is smaller than the sum of its proper divisors (3116916).

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

1993644 is a wasteful number, since it uses less digits than its factorization.

1993644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 790 (or 785 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 1993644 is about 1411.9645887911. The cubic root of 1993644 is about 125.8584957161.

The spelling of 1993644 in words is "one million, nine hundred ninety-three thousand, six hundred forty-four".