71857993 has 2 divisors, whose sum is σ = 71857994. Its totient is φ = 71857992.

The previous prime is 71857991. The next prime is 71857999. The reversal of 71857993 is 39975817.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69272329 + 2585664 = 8323^2 + 1608^2 .

It is a cyclic number.

It is not a de Polignac number, because 71857993 - 2¹ = 71857991 is a prime.

Together with 71857991, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (71857991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35928996 + 35928997.

It is an arithmetic number, because the mean of its divisors is an integer number (35928997).

Almost surely, 2^71857993 is an apocalyptic number.

It is an amenable number.

71857993 is a deficient number, since it is larger than the sum of its proper divisors (1).

71857993 is an equidigital number, since it uses as much as digits as its factorization.

71857993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 476280, while the sum is 49.

The square root of 71857993 is about 8476.9094014269. The cubic root of 71857993 is about 415.7430786147.

The spelling of 71857993 in words is "seventy-one million, eight hundred fifty-seven thousand, nine hundred ninety-three".