81002869 has 2 divisors, whose sum is σ = 81002870. Its totient is φ = 81002868.

The previous prime is 81002863. The next prime is 81002897. The reversal of 81002869 is 96820018.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72880369 + 8122500 = 8537^2 + 2850^2 .

It is a cyclic number.

It is not a de Polignac number, because 81002869 - 2⁷ = 81002741 is a prime.

It is a super-2 number, since 2×81002869² = 13122929572462322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81002863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40501434 + 40501435.

It is an arithmetic number, because the mean of its divisors is an integer number (40501435).

Almost surely, 2^81002869 is an apocalyptic number.

It is an amenable number.

81002869 is a deficient number, since it is larger than the sum of its proper divisors (1).

81002869 is an equidigital number, since it uses as much as digits as its factorization.

81002869 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 81002869 is about 9000.1593874775. The cubic root of 81002869 is about 432.6799794443.

The spelling of 81002869 in words is "eighty-one million, two thousand, eight hundred sixty-nine".