71537621 has 2 divisors, whose sum is σ = 71537622. Its totient is φ = 71537620.

The previous prime is 71537569. The next prime is 71537647. The reversal of 71537621 is 12673517.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69072721 + 2464900 = 8311^2 + 1570^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71537621 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71537321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35768810 + 35768811.

It is an arithmetic number, because the mean of its divisors is an integer number (35768811).

Almost surely, 2^71537621 is an apocalyptic number.

It is an amenable number.

71537621 is a deficient number, since it is larger than the sum of its proper divisors (1).

71537621 is an equidigital number, since it uses as much as digits as its factorization.

71537621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8820, while the sum is 32.

The square root of 71537621 is about 8457.9915464607. The cubic root of 71537621 is about 415.1243078527.

The spelling of 71537621 in words is "seventy-one million, five hundred thirty-seven thousand, six hundred twenty-one".