72002121 has 16 divisors (see below), whose sum is σ = 100704384. Its totient is φ = 45672704.

The previous prime is 72002107. The next prime is 72002149. The reversal of 72002121 is 12120027.

It is a cyclic number.

It is not a de Polignac number, because 72002121 - 2¹⁷ = 71871049 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 72002121.

It is not an unprimeable number, because it can be changed into a prime (72002171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10945 + ... + 16241.

It is an arithmetic number, because the mean of its divisors is an integer number (6294024).

Almost surely, 2^72002121 is an apocalyptic number.

It is an amenable number.

72002121 is a deficient number, since it is larger than the sum of its proper divisors (28702263).

72002121 is a wasteful number, since it uses less digits than its factorization.

72002121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5520.

The product of its (nonzero) digits is 56, while the sum is 15.

The square root of 72002121 is about 8485.4063544417. The cubic root of 72002121 is about 416.0208496238.

Adding to 72002121 its reverse (12120027), we get a palindrome (84122148).

The spelling of 72002121 in words is "seventy-two million, two thousand, one hundred twenty-one".