71887021 has 2 divisors, whose sum is σ = 71887022. Its totient is φ = 71887020.

The previous prime is 71887007. The next prime is 71887031. The reversal of 71887021 is 12078817.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42575625 + 29311396 = 6525^2 + 5414^2 .

It is a cyclic number.

It is not a de Polignac number, because 71887021 - 2⁹ = 71886509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71887031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35943510 + 35943511.

It is an arithmetic number, because the mean of its divisors is an integer number (35943511).

Almost surely, 2^71887021 is an apocalyptic number.

It is an amenable number.

71887021 is a deficient number, since it is larger than the sum of its proper divisors (1).

71887021 is an equidigital number, since it uses as much as digits as its factorization.

71887021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6272, while the sum is 34.

The square root of 71887021 is about 8478.6214091679. The cubic root of 71887021 is about 415.7990527423.

The spelling of 71887021 in words is "seventy-one million, eight hundred eighty-seven thousand, twenty-one".