81552061 has 2 divisors, whose sum is σ = 81552062. Its totient is φ = 81552060.

The previous prime is 81552049. The next prime is 81552073. The reversal of 81552061 is 16025518.

It is a balanced prime because it is at equal distance from previous prime (81552049) and next prime (81552073).

It can be written as a sum of positive squares in only one way, i.e., 77528025 + 4024036 = 8805^2 + 2006^2 .

It is a cyclic number.

It is not a de Polignac number, because 81552061 - 2¹¹ = 81550013 is a prime.

It is a super-3 number, since 3×81552061³ (a number of 25 digits) contains 333 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81552761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40776030 + 40776031.

It is an arithmetic number, because the mean of its divisors is an integer number (40776031).

Almost surely, 2^81552061 is an apocalyptic number.

It is an amenable number.

81552061 is a deficient number, since it is larger than the sum of its proper divisors (1).

81552061 is an equidigital number, since it uses as much as digits as its factorization.

81552061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2400, while the sum is 28.

The square root of 81552061 is about 9030.6179744246. The cubic root of 81552061 is about 433.6556213199.

Adding to 81552061 its reverse (16025518), we get a palindrome (97577579).

The spelling of 81552061 in words is "eighty-one million, five hundred fifty-two thousand, sixty-one".