71988641 has 2 divisors, whose sum is σ = 71988642. Its totient is φ = 71988640.

The previous prime is 71988617. The next prime is 71988649. The reversal of 71988641 is 14688917.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70980625 + 1008016 = 8425^2 + 1004^2 .

It is a cyclic number.

It is not a de Polignac number, because 71988641 - 2⁶ = 71988577 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 71988592 and 71988601.

It is not a weakly prime, because it can be changed into another prime (71988649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35994320 + 35994321.

It is an arithmetic number, because the mean of its divisors is an integer number (35994321).

Almost surely, 2^71988641 is an apocalyptic number.

It is an amenable number.

71988641 is a deficient number, since it is larger than the sum of its proper divisors (1).

71988641 is an equidigital number, since it uses as much as digits as its factorization.

71988641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96768, while the sum is 44.

The square root of 71988641 is about 8484.6120123433. The cubic root of 71988641 is about 415.9948859856.

The spelling of 71988641 in words is "seventy-one million, nine hundred eighty-eight thousand, six hundred forty-one".