4033720021 has 4 divisors (see below), whose sum is σ = 4033940652. Its totient is φ = 4033499392.

The previous prime is 4033719979. The next prime is 4033720037. The reversal of 4033720021 is 1200273304.

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 851180625 + 3182539396 = 29175^2 + 56414^2 .

It is a cyclic number.

It is not a de Polignac number, because 4033720021 - 2²⁷ = 3899502293 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 4033719974 and 4033720001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4033720421) 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 3 ways as a sum of consecutive naturals, for example, 80140 + ... + 120373.

It is an arithmetic number, because the mean of its divisors is an integer number (1008485163).

Almost surely, 2^4033720021 is an apocalyptic number.

It is an amenable number.

4033720021 is a deficient number, since it is larger than the sum of its proper divisors (220631).

4033720021 is a wasteful number, since it uses less digits than its factorization.

4033720021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220630.

The product of its (nonzero) digits is 1008, while the sum is 22.

The square root of 4033720021 is about 63511.5739137364. The cubic root of 4033720021 is about 1591.8491757836.

Adding to 4033720021 its reverse (1200273304), we get a palindrome (5233993325).

The spelling of 4033720021 in words is "four billion, thirty-three million, seven hundred twenty thousand, twenty-one".