71981755 has 4 divisors (see below), whose sum is σ = 86378112. Its totient is φ = 57585400.

The previous prime is 71981753. The next prime is 71981797. The reversal of 71981755 is 55718917.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55718917 = 263 ⋅211859.

It is not a de Polignac number, because 71981755 - 2¹ = 71981753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71981753) 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, 7198171 + ... + 7198180.

It is an arithmetic number, because the mean of its divisors is an integer number (21594528).

Almost surely, 2^71981755 is an apocalyptic number.

71981755 is a deficient number, since it is larger than the sum of its proper divisors (14396357).

71981755 is a wasteful number, since it uses less digits than its factorization.

71981755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14396356.

The product of its digits is 88200, while the sum is 43.

The square root of 71981755 is about 8484.2062091866. The cubic root of 71981755 is about 415.9816217072.

The spelling of 71981755 in words is "seventy-one million, nine hundred eighty-one thousand, seven hundred fifty-five".