81337601 has 2 divisors, whose sum is σ = 81337602. Its totient is φ = 81337600.

The previous prime is 81337567. The next prime is 81337603. The reversal of 81337601 is 10673318.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65529025 + 15808576 = 8095^2 + 3976^2 .

It is a cyclic number.

It is not a de Polignac number, because 81337601 - 2²⁶ = 14228737 is a prime.

Together with 81337603, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81337603) 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, 40668800 + 40668801.

It is an arithmetic number, because the mean of its divisors is an integer number (40668801).

Almost surely, 2^81337601 is an apocalyptic number.

It is an amenable number.

81337601 is a deficient number, since it is larger than the sum of its proper divisors (1).

81337601 is an equidigital number, since it uses as much as digits as its factorization.

81337601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 81337601 is about 9018.7361087904. The cubic root of 81337601 is about 433.2751550429.

The spelling of 81337601 in words is "eighty-one million, three hundred thirty-seven thousand, six hundred one".