71561645 has 8 divisors (see below), whose sum is σ = 85922304. Its totient is φ = 57217104.

The previous prime is 71561641. The next prime is 71561741. The reversal of 71561645 is 54616517.

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

It is a cyclic number.

It is not a de Polignac number, because 71561645 - 2² = 71561641 is a prime.

It is a super-3 number, since 3×71561645³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71561641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10532 + ... + 15938.

It is an arithmetic number, because the mean of its divisors is an integer number (10740288).

Almost surely, 2^71561645 is an apocalyptic number.

It is an amenable number.

71561645 is a deficient number, since it is larger than the sum of its proper divisors (14360659).

71561645 is a wasteful number, since it uses less digits than its factorization.

71561645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8059.

The product of its digits is 25200, while the sum is 35.

The square root of 71561645 is about 8459.4116225657. The cubic root of 71561645 is about 415.1707721236.

The spelling of 71561645 in words is "seventy-one million, five hundred sixty-one thousand, six hundred forty-five".