75115521 has 12 divisors (see below), whose sum is σ = 116846548. Its totient is φ = 46224864.

The previous prime is 75115517. The next prime is 75115529. The reversal of 75115521 is 12551157.

It can be written as a sum of positive squares in 2 ways, for example, as 12531600 + 62583921 = 3540^2 + 7911^2 .

It is not a de Polignac number, because 75115521 - 2² = 75115517 is a prime.

It is not an unprimeable number, because it can be changed into a prime (75115529) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 320890 + ... + 321123.

Almost surely, 2^75115521 is an apocalyptic number.

It is an amenable number.

75115521 is a deficient number, since it is larger than the sum of its proper divisors (41731027).

75115521 is a wasteful number, since it uses less digits than its factorization.

75115521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 642032 (or 642029 counting only the distinct ones).

The product of its digits is 1750, while the sum is 27.

The square root of 75115521 is about 8666.9210795991. The cubic root of 75115521 is about 421.9327419895.

Adding to 75115521 its reverse (12551157), we get a palindrome (87666678).

The spelling of 75115521 in words is "seventy-five million, one hundred fifteen thousand, five hundred twenty-one".