81731701 has 2 divisors, whose sum is σ = 81731702. Its totient is φ = 81731700.

The previous prime is 81731687. The next prime is 81731743. The reversal of 81731701 is 10713718.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80532676 + 1199025 = 8974^2 + 1095^2 .

It is a cyclic number.

It is not a de Polignac number, because 81731701 - 2⁵ = 81731669 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81731701.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81731791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40865850 + 40865851.

It is an arithmetic number, because the mean of its divisors is an integer number (40865851).

Almost surely, 2^81731701 is an apocalyptic number.

It is an amenable number.

81731701 is a deficient number, since it is larger than the sum of its proper divisors (1).

81731701 is an equidigital number, since it uses as much as digits as its factorization.

81731701 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1176, while the sum is 28.

The square root of 81731701 is about 9040.5586663657. The cubic root of 81731701 is about 433.9738015715.

The spelling of 81731701 in words is "eighty-one million, seven hundred thirty-one thousand, seven hundred one".