71747661 has 4 divisors (see below), whose sum is σ = 95663552. Its totient is φ = 47831772.

The previous prime is 71747639. The next prime is 71747677. The reversal of 71747661 is 16674717.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16674717 = 3 ⋅5558239.

It is not a de Polignac number, because 71747661 - 2⁹ = 71747149 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 (71747681) 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 3 ways as a sum of consecutive naturals, for example, 11957941 + ... + 11957946.

It is an arithmetic number, because the mean of its divisors is an integer number (23915888).

Almost surely, 2^71747661 is an apocalyptic number.

It is an amenable number.

71747661 is a deficient number, since it is larger than the sum of its proper divisors (23915891).

71747661 is a wasteful number, since it uses less digits than its factorization.

71747661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23915890.

The product of its digits is 49392, while the sum is 39.

The square root of 71747661 is about 8470.3991051190. The cubic root of 71747661 is about 415.5301899255.

The spelling of 71747661 in words is "seventy-one million, seven hundred forty-seven thousand, six hundred sixty-one".