71521021061 has 8 divisors (see below), whose sum is σ = 81942149184. Its totient is φ = 61150852800.

The previous prime is 71521020983. The next prime is 71521021069. The reversal of 71521021061 is 16012012517.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 71521021061 - 2³⁰ = 70447279237 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 71521021061.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71521021069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12736955 + ... + 12742568.

It is an arithmetic number, because the mean of its divisors is an integer number (10242768648).

Almost surely, 2^71521021061 is an apocalyptic number.

It is an amenable number.

71521021061 is a deficient number, since it is larger than the sum of its proper divisors (10421128123).

71521021061 is a wasteful number, since it uses less digits than its factorization.

71521021061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25479931.

The product of its (nonzero) digits is 840, while the sum is 26.

Adding to 71521021061 its reverse (16012012517), we get a palindrome (87533033578).

The spelling of 71521021061 in words is "seventy-one billion, five hundred twenty-one million, twenty-one thousand, sixty-one".