81682201 has 2 divisors, whose sum is σ = 81682202. Its totient is φ = 81682200.

The previous prime is 81682189. The next prime is 81682217. The reversal of 81682201 is 10228618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76387600 + 5294601 = 8740^2 + 2301^2 .

It is a cyclic number.

It is not a de Polignac number, because 81682201 - 2⁹ = 81681689 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81682201.

It is not a weakly prime, because it can be changed into another prime (81682231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40841100 + 40841101.

It is an arithmetic number, because the mean of its divisors is an integer number (40841101).

Almost surely, 2^81682201 is an apocalyptic number.

It is an amenable number.

81682201 is a deficient number, since it is larger than the sum of its proper divisors (1).

81682201 is an equidigital number, since it uses as much as digits as its factorization.

81682201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 81682201 is about 9037.8205890580. The cubic root of 81682201 is about 433.8861732253.

It can be divided in two parts, 8 and 1682201, that added together give a square (1682209 = 1297²).

The spelling of 81682201 in words is "eighty-one million, six hundred eighty-two thousand, two hundred one".