71939993 has 2 divisors, whose sum is σ = 71939994. Its totient is φ = 71939992.

The previous prime is 71939983. The next prime is 71940013. The reversal of 71939993 is 39993917.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54567769 + 17372224 = 7387^2 + 4168^2 .

It is a cyclic number.

It is not a de Polignac number, because 71939993 - 2⁸ = 71939737 is a prime.

It is not a weakly prime, because it can be changed into another prime (71939963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35969996 + 35969997.

It is an arithmetic number, because the mean of its divisors is an integer number (35969997).

Almost surely, 2^71939993 is an apocalyptic number.

It is an amenable number.

71939993 is a deficient number, since it is larger than the sum of its proper divisors (1).

71939993 is an equidigital number, since it uses as much as digits as its factorization.

71939993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 413343, while the sum is 50.

The square root of 71939993 is about 8481.7446908051. The cubic root of 71939993 is about 415.9011587935.

The spelling of 71939993 in words is "seventy-one million, nine hundred thirty-nine thousand, nine hundred ninety-three".