71971157 has 2 divisors, whose sum is σ = 71971158. Its totient is φ = 71971156.

The previous prime is 71971139. The next prime is 71971189. The reversal of 71971157 is 75117917.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60855601 + 11115556 = 7801^2 + 3334^2 .

It is a cyclic number.

It is not a de Polignac number, because 71971157 - 2⁶ = 71971093 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 71971157.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71971457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35985578 + 35985579.

It is an arithmetic number, because the mean of its divisors is an integer number (35985579).

Almost surely, 2^71971157 is an apocalyptic number.

It is an amenable number.

71971157 is a deficient number, since it is larger than the sum of its proper divisors (1).

71971157 is an equidigital number, since it uses as much as digits as its factorization.

71971157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15435, while the sum is 38.

The square root of 71971157 is about 8483.5816139176. The cubic root of 71971157 is about 415.9612054707.

The spelling of 71971157 in words is "seventy-one million, nine hundred seventy-one thousand, one hundred fifty-seven".