71993081 has 2 divisors, whose sum is σ = 71993082. Its totient is φ = 71993080.

The previous prime is 71993063. The next prime is 71993093. The reversal of 71993081 is 18039917.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58369600 + 13623481 = 7640^2 + 3691^2 .

It is a cyclic number.

It is not a de Polignac number, because 71993081 - 2⁶ = 71993017 is a prime.

It is a super-2 number, since 2×71993081² = 10366007423745122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (71993021) 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 as a sum of consecutive naturals, namely, 35996540 + 35996541.

It is an arithmetic number, because the mean of its divisors is an integer number (35996541).

Almost surely, 2^71993081 is an apocalyptic number.

It is an amenable number.

71993081 is a deficient number, since it is larger than the sum of its proper divisors (1).

71993081 is an equidigital number, since it uses as much as digits as its factorization.

71993081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13608, while the sum is 38.

The square root of 71993081 is about 8484.8736584583. The cubic root of 71993081 is about 416.0034381650.

The spelling of 71993081 in words is "seventy-one million, nine hundred ninety-three thousand, eighty-one".