81475201 has 2 divisors, whose sum is σ = 81475202. Its totient is φ = 81475200.

The previous prime is 81475189. The next prime is 81475217. The reversal of 81475201 is 10257418.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50126400 + 31348801 = 7080^2 + 5599^2 .

It is a cyclic number.

It is not a de Polignac number, because 81475201 - 2⁹ = 81474689 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81475201.

It is not a weakly prime, because it can be changed into another prime (81475001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40737600 + 40737601.

It is an arithmetic number, because the mean of its divisors is an integer number (40737601).

Almost surely, 2^81475201 is an apocalyptic number.

It is an amenable number.

81475201 is a deficient number, since it is larger than the sum of its proper divisors (1).

81475201 is an equidigital number, since it uses as much as digits as its factorization.

81475201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 81475201 is about 9026.3614485572. The cubic root of 81475201 is about 433.5193433515.

The spelling of 81475201 in words is "eighty-one million, four hundred seventy-five thousand, two hundred one".