81952069 has 2 divisors, whose sum is σ = 81952070. Its totient is φ = 81952068.

The previous prime is 81952061. The next prime is 81952139. The reversal of 81952069 is 96025918.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76335169 + 5616900 = 8737^2 + 2370^2 .

It is a cyclic number.

It is not a de Polignac number, because 81952069 - 2³ = 81952061 is a prime.

It is a super-2 number, since 2×81952069² = 13432283226761522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81952061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40976034 + 40976035.

It is an arithmetic number, because the mean of its divisors is an integer number (40976035).

Almost surely, 2^81952069 is an apocalyptic number.

It is an amenable number.

81952069 is a deficient number, since it is larger than the sum of its proper divisors (1).

81952069 is an equidigital number, since it uses as much as digits as its factorization.

81952069 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38880, while the sum is 40.

The square root of 81952069 is about 9052.7382045434. The cubic root of 81952069 is about 434.3634835654.

The spelling of 81952069 in words is "eighty-one million, nine hundred fifty-two thousand, sixty-nine".