71525521 has 4 divisors (see below), whose sum is σ = 71577072. Its totient is φ = 71473972.

The previous prime is 71525501. The next prime is 71525539. The reversal of 71525521 is 12552517.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 71525521 - 2⁷ = 71525393 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71525521.

It is not an unprimeable number, because it can be changed into a prime (71525501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23635 + ... + 26488.

It is an arithmetic number, because the mean of its divisors is an integer number (17894268).

Almost surely, 2^71525521 is an apocalyptic number.

It is an amenable number.

71525521 is a deficient number, since it is larger than the sum of its proper divisors (51551).

71525521 is a wasteful number, since it uses less digits than its factorization.

71525521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51550.

The product of its digits is 3500, while the sum is 28.

The square root of 71525521 is about 8457.2762163713. The cubic root of 71525521 is about 415.1009015793.

The spelling of 71525521 in words is "seventy-one million, five hundred twenty-five thousand, five hundred twenty-one".