71043661 has 16 divisors (see below), whose sum is σ = 79511040. Its totient is φ = 63034560.

The previous prime is 71043631. The next prime is 71043677. The reversal of 71043661 is 16634017.

It is a cyclic number.

It is not a de Polignac number, because 71043661 - 2⁹ = 71043149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71043631) 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 in 15 ways as a sum of consecutive naturals, for example, 69210 + ... + 70228.

It is an arithmetic number, because the mean of its divisors is an integer number (4969440).

Almost surely, 2^71043661 is an apocalyptic number.

It is an amenable number.

71043661 is a deficient number, since it is larger than the sum of its proper divisors (8467379).

71043661 is a wasteful number, since it uses less digits than its factorization.

71043661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1236.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 71043661 is about 8428.7401786981. The cubic root of 71043661 is about 414.1666365373.

Adding to 71043661 its reverse (16634017), we get a palindrome (87677678).

The spelling of 71043661 in words is "seventy-one million, forty-three thousand, six hundred sixty-one".