75513521 has 4 divisors (see below), whose sum is σ = 75752052. Its totient is φ = 75274992.

The previous prime is 75513517. The next prime is 75513527. The reversal of 75513521 is 12531557.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12531557 = 1123 ⋅11159.

It can be written as a sum of positive squares in 2 ways, for example, as 15295921 + 60217600 = 3911^2 + 7760^2 .

It is a cyclic number.

It is not a de Polignac number, because 75513521 - 2² = 75513517 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (75513527) 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 3 ways as a sum of consecutive naturals, for example, 118790 + ... + 119423.

It is an arithmetic number, because the mean of its divisors is an integer number (18938013).

Almost surely, 2^75513521 is an apocalyptic number.

It is an amenable number.

75513521 is a deficient number, since it is larger than the sum of its proper divisors (238531).

75513521 is a wasteful number, since it uses less digits than its factorization.

75513521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238530.

The product of its digits is 5250, while the sum is 29.

The square root of 75513521 is about 8689.8516097802. The cubic root of 75513521 is about 422.6766340096.

The spelling of 75513521 in words is "seventy-five million, five hundred thirteen thousand, five hundred twenty-one".