71631457 has 2 divisors, whose sum is σ = 71631458. Its totient is φ = 71631456.

The previous prime is 71631449. The next prime is 71631473. The reversal of 71631457 is 75413617.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71216721 + 414736 = 8439^2 + 644^2 .

It is an emirp because it is prime and its reverse (75413617) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71631457 - 2³ = 71631449 is a prime.

It is not a weakly prime, because it can be changed into another prime (71331457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35815728 + 35815729.

It is an arithmetic number, because the mean of its divisors is an integer number (35815729).

Almost surely, 2^71631457 is an apocalyptic number.

It is an amenable number.

71631457 is a deficient number, since it is larger than the sum of its proper divisors (1).

71631457 is an equidigital number, since it uses as much as digits as its factorization.

71631457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17640, while the sum is 34.

The square root of 71631457 is about 8463.5369084089. The cubic root of 71631457 is about 415.3057349329.

The spelling of 71631457 in words is "seventy-one million, six hundred thirty-one thousand, four hundred fifty-seven".