81206737 has 2 divisors, whose sum is σ = 81206738. Its totient is φ = 81206736.

The previous prime is 81206693. The next prime is 81206771. The reversal of 81206737 is 73760218.

It is an a-pointer prime, because the next prime (81206771) can be obtained adding 81206737 to its sum of digits (34).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56565441 + 24641296 = 7521^2 + 4964^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81206737 is a prime.

It is not a weakly prime, because it can be changed into another prime (81206137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40603368 + 40603369.

It is an arithmetic number, because the mean of its divisors is an integer number (40603369).

Almost surely, 2^81206737 is an apocalyptic number.

It is an amenable number.

81206737 is a deficient number, since it is larger than the sum of its proper divisors (1).

81206737 is an equidigital number, since it uses as much as digits as its factorization.

81206737 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14112, while the sum is 34.

The square root of 81206737 is about 9011.4780696620. The cubic root of 81206737 is about 433.0426649659.

The spelling of 81206737 in words is "eighty-one million, two hundred six thousand, seven hundred thirty-seven".