4001213121 has 32 divisors (see below), whose sum is σ = 5589319680. Its totient is φ = 2543049600.

The previous prime is 4001213119. The next prime is 4001213123. The reversal of 4001213121 is 1213121004.

It is an interprime number because it is at equal distance from previous prime (4001213119) and next prime (4001213123).

It is not a de Polignac number, because 4001213121 - 2¹ = 4001213119 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 4001213121.

It is not an unprimeable number, because it can be changed into a prime (4001213123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4391656 + ... + 4392566.

It is an arithmetic number, because the mean of its divisors is an integer number (174666240).

Almost surely, 2^4001213121 is an apocalyptic number.

It is an amenable number.

4001213121 is a deficient number, since it is larger than the sum of its proper divisors (1588106559).

4001213121 is a wasteful number, since it uses less digits than its factorization.

4001213121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1597.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 4001213121 is about 63255.1430399142. The cubic root of 4001213121 is about 1587.5615115438.

Adding to 4001213121 its reverse (1213121004), we get a palindrome (5214334125).

The spelling of 4001213121 in words is "four billion, one million, two hundred thirteen thousand, one hundred twenty-one".