81603061 has 2 divisors, whose sum is σ = 81603062. Its totient is φ = 81603060.

The previous prime is 81603037. The next prime is 81603073. The reversal of 81603061 is 16030618.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 81558961 + 44100 = 9031^2 + 210^2 .

It is a cyclic number.

It is not a de Polignac number, because 81603061 - 2⁵ = 81603029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81601061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40801530 + 40801531.

It is an arithmetic number, because the mean of its divisors is an integer number (40801531).

Almost surely, 2^81603061 is an apocalyptic number.

It is an amenable number.

81603061 is a deficient number, since it is larger than the sum of its proper divisors (1).

81603061 is an equidigital number, since it uses as much as digits as its factorization.

81603061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 81603061 is about 9033.4412601179. The cubic root of 81603061 is about 433.7460005113.

Adding to 81603061 its reverse (16030618), we get a palindrome (97633679).

The spelling of 81603061 in words is "eighty-one million, six hundred three thousand, sixty-one".