71144380781 has 4 divisors (see below), whose sum is σ = 74237614752. Its totient is φ = 68051146812.

The previous prime is 71144380777. The next prime is 71144380793. The reversal of 71144380781 is 18708344117.

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.

It is a cyclic number.

It is not a de Polignac number, because 71144380781 - 2² = 71144380777 is a prime.

It is a super-2 number, since 2×71144380781² (a number of 23 digits) contains 22 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 (71144380711) 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, 1546616951 + ... + 1546616996.

It is an arithmetic number, because the mean of its divisors is an integer number (18559403688).

Almost surely, 2^71144380781 is an apocalyptic number.

It is an amenable number.

71144380781 is a deficient number, since it is larger than the sum of its proper divisors (3093233971).

71144380781 is a wasteful number, since it uses less digits than its factorization.

71144380781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3093233970.

The product of its (nonzero) digits is 150528, while the sum is 44.

The spelling of 71144380781 in words is "seventy-one billion, one hundred forty-four million, three hundred eighty thousand, seven hundred eighty-one".