71561613 has 8 divisors (see below), whose sum is σ = 95699968. Its totient is φ = 47565504.

The previous prime is 71561599. The next prime is 71561621. The reversal of 71561613 is 31616517.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 71561613 - 2⁶ = 71561549 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 (71566613) 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 in 7 ways as a sum of consecutive naturals, for example, 34381 + ... + 36402.

It is an arithmetic number, because the mean of its divisors is an integer number (11962496).

Almost surely, 2^71561613 is an apocalyptic number.

It is an amenable number.

71561613 is a deficient number, since it is larger than the sum of its proper divisors (24138355).

71561613 is a wasteful number, since it uses less digits than its factorization.

71561613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71123.

The product of its digits is 3780, while the sum is 30.

The square root of 71561613 is about 8459.4097311810. The cubic root of 71561613 is about 415.1707102400.

The spelling of 71561613 in words is "seventy-one million, five hundred sixty-one thousand, six hundred thirteen".