71504561 has 2 divisors, whose sum is σ = 71504562. Its totient is φ = 71504560.

The previous prime is 71504549. The next prime is 71504591. The reversal of 71504561 is 16540517.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71503936 + 625 = 8456^2 + 25^2 .

It is a cyclic number.

It is not a de Polignac number, because 71504561 - 2⁶ = 71504497 is a prime.

It is a super-2 number, since 2×71504561² = 10225804487605442, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (71504501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35752280 + 35752281.

It is an arithmetic number, because the mean of its divisors is an integer number (35752281).

Almost surely, 2^71504561 is an apocalyptic number.

It is an amenable number.

71504561 is a deficient number, since it is larger than the sum of its proper divisors (1).

71504561 is an equidigital number, since it uses as much as digits as its factorization.

71504561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4200, while the sum is 29.

The square root of 71504561 is about 8456.0369559268. The cubic root of 71504561 is about 415.0603502498.

It can be divided in two parts, 7150 and 4561, that added together give a palindrome (11711).

The spelling of 71504561 in words is "seventy-one million, five hundred four thousand, five hundred sixty-one".