71521523 has 4 divisors (see below), whose sum is σ = 71568288. Its totient is φ = 71474760.

The previous prime is 71521519. The next prime is 71521537. The reversal of 71521523 is 32512517.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 71521523 - 2² = 71521519 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 71521492 and 71521501.

It is not an unprimeable number, because it can be changed into a prime (71521573) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21008 + ... + 24173.

It is an arithmetic number, because the mean of its divisors is an integer number (17892072).

Almost surely, 2^71521523 is an apocalyptic number.

71521523 is a deficient number, since it is larger than the sum of its proper divisors (46765).

71521523 is a wasteful number, since it uses less digits than its factorization.

71521523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46764.

The product of its digits is 2100, while the sum is 26.

The square root of 71521523 is about 8457.0398485522. The cubic root of 71521523 is about 415.0931672568.

The spelling of 71521523 in words is "seventy-one million, five hundred twenty-one thousand, five hundred twenty-three".