4491981 has 12 divisors (see below), whose sum is σ = 6987708. Its totient is φ = 2764224.

The previous prime is 4491953. The next prime is 4491989. The reversal of 4491981 is 1891944.

It can be written as a sum of positive squares in 2 ways, for example, as 1010025 + 3481956 = 1005^2 + 1866^2 .

It is not a de Polignac number, because 4491981 - 2⁹ = 4491469 is a prime.

It is a super-2 number, since 2×4491981² = 40355786608722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4491989) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19080 + ... + 19313.

It is an arithmetic number, because the mean of its divisors is an integer number (582309).

Almost surely, 2^4491981 is an apocalyptic number.

It is an amenable number.

4491981 is a deficient number, since it is larger than the sum of its proper divisors (2495727).

4491981 is a wasteful number, since it uses less digits than its factorization.

4491981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38412 (or 38409 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 4491981 is about 2119.4294043445. The cubic root of 4491981 is about 164.9982368958.

The spelling of 4491981 in words is "four million, four hundred ninety-one thousand, nine hundred eighty-one".