71561801 has 4 divisors (see below), whose sum is σ = 71828100. Its totient is φ = 71295504.

The previous prime is 71561797. The next prime is 71561839. The reversal of 71561801 is 10816517.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 10816517 = 163 ⋅66359.

It can be written as a sum of positive squares in 2 ways, for example, as 34339600 + 37222201 = 5860^2 + 6101^2 .

It is a cyclic number.

It is not a de Polignac number, because 71561801 - 2² = 71561797 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71563801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 132746 + ... + 133283.

It is an arithmetic number, because the mean of its divisors is an integer number (17957025).

Almost surely, 2^71561801 is an apocalyptic number.

It is an amenable number.

71561801 is a deficient number, since it is larger than the sum of its proper divisors (266299).

71561801 is a wasteful number, since it uses less digits than its factorization.

71561801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266298.

The product of its (nonzero) digits is 1680, while the sum is 29.

The square root of 71561801 is about 8459.4208430601. The cubic root of 71561801 is about 415.1710738056.

The spelling of 71561801 in words is "seventy-one million, five hundred sixty-one thousand, eight hundred one".