3991104 has 126 divisors (see below), whose sum is σ = 12689586. Its totient is φ = 1198080.

The previous prime is 3991103. The next prime is 3991111. The reversal of 3991104 is 4011993.

It can be written as a sum of positive squares in 3 ways, for example, as 304704 + 3686400 = 552^2 + 1920^2 .

It is a super-2 number, since 2×3991104² = 31857822277632, which contains 22 as substring.

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3991103) 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, 97324 + ... + 97364.

It is an arithmetic number, because the mean of its divisors is an integer number (100711).

Almost surely, 2^3991104 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 3991104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6344793).

3991104 is an abundant number, since it is smaller than the sum of its proper divisors (8698482).

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

3991104 is a wasteful number, since it uses less digits than its factorization.

3991104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85 (or 59 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 3991104 is about 1997.7747620790. The cubic root of 3991104 is about 158.6223385179.

It can be divided in two parts, 3991 and 104, that added together give a triangular number (4095 = T₉₀).

The spelling of 3991104 in words is "three million, nine hundred ninety-one thousand, one hundred four".