71031881 has 4 divisors (see below), whose sum is σ = 73323264. Its totient is φ = 68740500.

The previous prime is 71031853. The next prime is 71031887. The reversal of 71031881 is 18813017.

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 71031881 - 2¹⁰ = 71030857 is a prime.

It is a super-2 number, since 2×71031881² = 10091056236796322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (71031887) 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, 1145645 + ... + 1145706.

It is an arithmetic number, because the mean of its divisors is an integer number (18330816).

Almost surely, 2^71031881 is an apocalyptic number.

It is an amenable number.

71031881 is a deficient number, since it is larger than the sum of its proper divisors (2291383).

71031881 is a wasteful number, since it uses less digits than its factorization.

71031881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2291382.

The product of its (nonzero) digits is 1344, while the sum is 29.

The square root of 71031881 is about 8428.0413501596. The cubic root of 71031881 is about 414.1437437950.

Adding to 71031881 its reverse (18813017), we get a palindrome (89844898).

The spelling of 71031881 in words is "seventy-one million, thirty-one thousand, eight hundred eighty-one".