4012003021 has 4 divisors (see below), whose sum is σ = 4320618652. Its totient is φ = 3703387392.

The previous prime is 4012002989. The next prime is 4012003027. The reversal of 4012003021 is 1203002104.

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 458174025 + 3553828996 = 21405^2 + 59614^2 .

It is a cyclic number.

It is not a de Polignac number, because 4012003021 - 2⁵ = 4012002989 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 308615617 = 4012003021 / (4 + 0 + 1 + 2 + 0 + 0 + 3 + 0 + 2 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 4012002992 and 4012003010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4012003027) 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, 154307796 + ... + 154307821.

It is an arithmetic number, because the mean of its divisors is an integer number (1080154663).

Almost surely, 2^4012003021 is an apocalyptic number.

It is an amenable number.

4012003021 is a deficient number, since it is larger than the sum of its proper divisors (308615631).

4012003021 is a wasteful number, since it uses less digits than its factorization.

4012003021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308615630.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 4012003021 is about 63340.3743358058. The cubic root of 4012003021 is about 1588.9872670904.

Adding to 4012003021 its reverse (1203002104), we get a palindrome (5215005125).

The spelling of 4012003021 in words is "four billion, twelve million, three thousand, twenty-one".