71113037561 has 16 divisors (see below), whose sum is σ = 74847181200. Its totient is φ = 67466649600.

The previous prime is 71113037557. The next prime is 71113037573. The reversal of 71113037561 is 16573031117.

It can be written as a sum of positive squares in 8 ways, for example, as 16225919161 + 54887118400 = 127381^2 + 234280^2 .

It is a cyclic number.

It is not a de Polignac number, because 71113037561 - 2² = 71113037557 is a prime.

It is a super-2 number, since 2×71113037561² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71113037461) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1765001 + ... + 1804841.

It is an arithmetic number, because the mean of its divisors is an integer number (4677948825).

Almost surely, 2^71113037561 is an apocalyptic number.

It is an amenable number.

71113037561 is a deficient number, since it is larger than the sum of its proper divisors (3734143639).

71113037561 is a wasteful number, since it uses less digits than its factorization.

71113037561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40940.

The product of its (nonzero) digits is 13230, while the sum is 35.

Adding to 71113037561 its reverse (16573031117), we get a palindrome (87686068678).

The spelling of 71113037561 in words is "seventy-one billion, one hundred thirteen million, thirty-seven thousand, five hundred sixty-one".