7220138 has 16 divisors (see below), whose sum is σ = 11628360. Its totient is φ = 3350016.

The previous prime is 7220131. The next prime is 7220149. The reversal of 7220138 is 8310227.

It can be written as a sum of positive squares in 4 ways, for example, as 7219969 + 169 = 2687^2 + 13^2 .

It is an Ulam number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (7220131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1028 + ... + 3936.

Almost surely, 2^7220138 is an apocalyptic number.

7220138 is a deficient number, since it is larger than the sum of its proper divisors (4408222).

7220138 is a wasteful number, since it uses less digits than its factorization.

7220138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3001.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 7220138 is about 2687.0314475272. The cubic root of 7220138 is about 193.2777373500.

The spelling of 7220138 in words is "seven million, two hundred twenty thousand, one hundred thirty-eight".