71755981 has 8 divisors (see below), whose sum is σ = 79945344. Its totient is φ = 63844320.

The previous prime is 71755973. The next prime is 71755991. The reversal of 71755981 is 18955717.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 71755981 - 2³ = 71755973 is a prime.

It is a super-2 number, since 2×71755981² = 10297841618544722, which 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 (71755921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68880 + ... + 69913.

It is an arithmetic number, because the mean of its divisors is an integer number (9993168).

Almost surely, 2^71755981 is an apocalyptic number.

It is an amenable number.

71755981 is a deficient number, since it is larger than the sum of its proper divisors (8189363).

71755981 is a wasteful number, since it uses less digits than its factorization.

71755981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138851.

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

The square root of 71755981 is about 8470.8902129587. The cubic root of 71755981 is about 415.5462512043.

The spelling of 71755981 in words is "seventy-one million, seven hundred fifty-five thousand, nine hundred eighty-one".