4021223121 has 6 divisors (see below), whose sum is σ = 5808433410. Its totient is φ = 2680815408.

The previous prime is 4021223117. The next prime is 4021223149. The reversal of 4021223121 is 1213221204.

It is a happy number.

4021223121 is a `hidden beast` number, since 402 + 12 + 231 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2026350225 + 1994872896 = 45015^2 + 44664^2 .

It is not a de Polignac number, because 4021223121 - 2² = 4021223117 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 4021223094 and 4021223103.

It is not an unprimeable number, because it can be changed into a prime (4021221121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 223401276 + ... + 223401293.

It is an arithmetic number, because the mean of its divisors is an integer number (968072235).

Almost surely, 2^4021223121 is an apocalyptic number.

It is an amenable number.

4021223121 is a deficient number, since it is larger than the sum of its proper divisors (1787210289).

4021223121 is a wasteful number, since it uses less digits than its factorization.

4021223121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446802575 (or 446802572 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 4021223121 is about 63413.1147397760. The cubic root of 4021223121 is about 1590.2035683349.

Adding to 4021223121 its reverse (1213221204), we get a palindrome (5234444325).

The spelling of 4021223121 in words is "four billion, twenty-one million, two hundred twenty-three thousand, one hundred twenty-one".