4121981 has 4 divisors (see below), whose sum is σ = 4134012. Its totient is φ = 4109952.

The previous prime is 4121959. The next prime is 4121987. The reversal of 4121981 is 1891214.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2669956 + 1452025 = 1634^2 + 1205^2 .

It is a cyclic number.

It is not a de Polignac number, because 4121981 - 2¹⁰ = 4120957 is a prime.

It is a super-2 number, since 2×4121981² = 33981454728722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 4121981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4121987) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5486 + ... + 6191.

It is an arithmetic number, because the mean of its divisors is an integer number (1033503).

Almost surely, 2^4121981 is an apocalyptic number.

It is an amenable number.

4121981 is a deficient number, since it is larger than the sum of its proper divisors (12031).

4121981 is a wasteful number, since it uses less digits than its factorization.

4121981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12030.

The product of its digits is 576, while the sum is 26.

The square root of 4121981 is about 2030.2662386988. The cubic root of 4121981 is about 160.3375815119.

It can be divided in two parts, 41 and 21981, that added together give a palindrome (22022).

The spelling of 4121981 in words is "four million, one hundred twenty-one thousand, nine hundred eighty-one".