71143561 has 2 divisors, whose sum is σ = 71143562. Its totient is φ = 71143560.

The previous prime is 71143547. The next prime is 71143573. The reversal of 71143561 is 16534117.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58675600 + 12467961 = 7660^2 + 3531^2 .

It is a cyclic number.

It is not a de Polignac number, because 71143561 - 2⁷ = 71143433 is a prime.

It is a super-2 number, since 2×71143561² = 10122812543521442, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (71143361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35571780 + 35571781.

It is an arithmetic number, because the mean of its divisors is an integer number (35571781).

Almost surely, 2^71143561 is an apocalyptic number.

It is an amenable number.

71143561 is a deficient number, since it is larger than the sum of its proper divisors (1).

71143561 is an equidigital number, since it uses as much as digits as its factorization.

71143561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2520, while the sum is 28.

The square root of 71143561 is about 8434.6642493937. The cubic root of 71143561 is about 414.3606762208.

Adding to 71143561 its reverse (16534117), we get a palindrome (87677678).

The spelling of 71143561 in words is "seventy-one million, one hundred forty-three thousand, five hundred sixty-one".