71601521 has 4 divisors (see below), whose sum is σ = 71645412. Its totient is φ = 71557632.

The previous prime is 71601451. The next prime is 71601529. The reversal of 71601521 is 12510617.

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

It can be written as a sum of positive squares in 2 ways, for example, as 57456400 + 14145121 = 7580^2 + 3761^2 .

It is a cyclic number.

It is not a de Polignac number, because 71601521 - 2¹⁰ = 71600497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71601529) 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, 19400 + ... + 22793.

It is an arithmetic number, because the mean of its divisors is an integer number (17911353).

Almost surely, 2^71601521 is an apocalyptic number.

It is an amenable number.

71601521 is a deficient number, since it is larger than the sum of its proper divisors (43891).

71601521 is a wasteful number, since it uses less digits than its factorization.

71601521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43890.

The product of its (nonzero) digits is 420, while the sum is 23.

The square root of 71601521 is about 8461.7681958324. The cubic root of 71601521 is about 415.2478724363.

The spelling of 71601521 in words is "seventy-one million, six hundred one thousand, five hundred twenty-one".