1663992 has 72 divisors (see below), whose sum is σ = 4979520. Its totient is φ = 501600.

The previous prime is 1663973. The next prime is 1663997. The reversal of 1663992 is 2993661.

1663992 is a `hidden beast` number, since 16 + 639 + 9 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

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 congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663997) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 8617 + ... + 8807.

It is an arithmetic number, because the mean of its divisors is an integer number (69160).

2^1663992 is an apocalyptic number.

1663992 is a gapful number since it is divisible by the number (12) 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 1663992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2489760).

1663992 is an abundant number, since it is smaller than the sum of its proper divisors (3315528).

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

1663992 is a wasteful number, since it uses less digits than its factorization.

1663992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225 (or 207 counting only the distinct ones).

The product of its digits is 17496, while the sum is 36.

The square root of 1663992 is about 1289.9581388557. The cubic root of 1663992 is about 118.4996528324.

The spelling of 1663992 in words is "one million, six hundred sixty-three thousand, nine hundred ninety-two".