71187009021 has 24 divisors (see below), whose sum is σ = 106785389880. Its totient is φ = 45643186176.

The previous prime is 71187009017. The next prime is 71187009031. The reversal of 71187009021 is 12090078117.

It can be written as a sum of positive squares in 4 ways, for example, as 54342603225 + 16844405796 = 233115^2 + 129786^2 .

It is not a de Polignac number, because 71187009021 - 2² = 71187009017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71187009031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 463560 + ... + 597713.

It is an arithmetic number, because the mean of its divisors is an integer number (4449391245).

Almost surely, 2^71187009021 is an apocalyptic number.

It is an amenable number.

71187009021 is a deficient number, since it is larger than the sum of its proper divisors (35598380859).

71187009021 is a wasteful number, since it uses less digits than its factorization.

71187009021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1061565 (or 1061562 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 36.

The spelling of 71187009021 in words is "seventy-one billion, one hundred eighty-seven million, nine thousand, twenty-one".