4991000 has 128 divisors (see below), whose sum is σ = 14376960. Its totient is φ = 1584000.

The previous prime is 4990981. The next prime is 4991009. The reversal of 4991000 is 1994.

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 a Harshad number since it is a multiple of its sum of digits (23).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4991009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 160985 + ... + 161015.

It is an arithmetic number, because the mean of its divisors is an integer number (112320).

Almost surely, 2^4991000 is an apocalyptic number.

4991000 is a gapful number since it is divisible by the number (40) 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 4991000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7188480).

4991000 is an abundant number, since it is smaller than the sum of its proper divisors (9385960).

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

4991000 is a wasteful number, since it uses less digits than its factorization.

4991000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82 (or 68 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 4991000 is about 2234.0546098965. The cubic root of 4991000 is about 170.8949344901.

Adding to 4991000 its reverse (1994), we get a palindrome (4992994).

The spelling of 4991000 in words is "four million, nine hundred ninety-one thousand".