7215138 has 48 divisors (see below), whose sum is σ = 18023616. Its totient is φ = 2043360.

The previous prime is 7215133. The next prime is 7215167. The reversal of 7215138 is 8315127.

It is not an unprimeable number, because it can be changed into a prime (7215133) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21633 + ... + 21963.

It is an arithmetic number, because the mean of its divisors is an integer number (375492).

Almost surely, 2^7215138 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7215138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9011808).

7215138 is an abundant number, since it is smaller than the sum of its proper divisors (10808478).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7215138 is a wasteful number, since it uses less digits than its factorization.

7215138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 519 (or 516 counting only the distinct ones).

The product of its digits is 1680, while the sum is 27.

The square root of 7215138 is about 2686.1008916271. The cubic root of 7215138 is about 193.2331116171.

It can be divided in two parts, 72 and 15138, that multiplied together give a square (1089936 = 1044²).

The spelling of 7215138 in words is "seven million, two hundred fifteen thousand, one hundred thirty-eight".