9215138 has 4 divisors (see below), whose sum is σ = 13822710. Its totient is φ = 4607568.

The previous prime is 9215137. The next prime is 9215159. The reversal of 9215138 is 8315129.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8315129 = 1427 ⋅5827.

It can be written as a sum of positive squares in only one way, i.e., 7491169 + 1723969 = 2737^2 + 1313^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 9215138.

It is not an unprimeable number, because it can be changed into a prime (9215137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2303783 + ... + 2303786.

Almost surely, 2^9215138 is an apocalyptic number.

9215138 is a deficient number, since it is larger than the sum of its proper divisors (4607572).

9215138 is a wasteful number, since it uses less digits than its factorization.

9215138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4607571.

The product of its digits is 2160, while the sum is 29.

The square root of 9215138 is about 3035.6445773509. The cubic root of 9215138 is about 209.6527746457.

Subtracting from 9215138 its reverse (8315129), we obtain a palindrome (900009).

The spelling of 9215138 in words is "nine million, two hundred fifteen thousand, one hundred thirty-eight".