4004991 has 32 divisors (see below), whose sum is σ = 6444800. Its totient is φ = 2449440.

The previous prime is 4004989. The next prime is 4005019. The reversal of 4004991 is 1994004.

It is not a de Polignac number, because 4004991 - 2¹ = 4004989 is a prime.

It is a hoax number, since the sum of its digits (27) 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 (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4004951) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18876 + ... + 19086.

It is an arithmetic number, because the mean of its divisors is an integer number (201400).

Almost surely, 2^4004991 is an apocalyptic number.

4004991 is the 1266-th heptagonal number.

4004991 is a deficient number, since it is larger than the sum of its proper divisors (2439809).

4004991 is a wasteful number, since it uses less digits than its factorization.

4004991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276 (or 270 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 4004991 is about 2001.2473610226. The cubic root of 4004991 is about 158.8061004113.

Adding to 4004991 its reverse (1994004), we get a palindrome (5998995).

The spelling of 4004991 in words is "four million, four thousand, nine hundred ninety-one".