71728842637 has 2 divisors, whose sum is σ = 71728842638. Its totient is φ = 71728842636.

The previous prime is 71728842629. The next prime is 71728842649. The reversal of 71728842637 is 73624882717.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65502212356 + 6226630281 = 255934^2 + 78909^2 .

It is a cyclic number.

It is not a de Polignac number, because 71728842637 - 2³ = 71728842629 is a prime.

It is a super-2 number, since 2×71728842637² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71728842697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35864421318 + 35864421319.

It is an arithmetic number, because the mean of its divisors is an integer number (35864421319).

Almost surely, 2^71728842637 is an apocalyptic number.

It is an amenable number.

71728842637 is a deficient number, since it is larger than the sum of its proper divisors (1).

71728842637 is an equidigital number, since it uses as much as digits as its factorization.

71728842637 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6322176, while the sum is 55.

The spelling of 71728842637 in words is "seventy-one billion, seven hundred twenty-eight million, eight hundred forty-two thousand, six hundred thirty-seven".