81374617 has 2 divisors, whose sum is σ = 81374618. Its totient is φ = 81374616.

The previous prime is 81374599. The next prime is 81374639. The reversal of 81374617 is 71647318.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64899136 + 16475481 = 8056^2 + 4059^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81374617 is a prime.

It is not a weakly prime, because it can be changed into another prime (81374647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40687308 + 40687309.

It is an arithmetic number, because the mean of its divisors is an integer number (40687309).

Almost surely, 2^81374617 is an apocalyptic number.

It is an amenable number.

81374617 is a deficient number, since it is larger than the sum of its proper divisors (1).

81374617 is an equidigital number, since it uses as much as digits as its factorization.

81374617 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28224, while the sum is 37.

The square root of 81374617 is about 9020.7880476154. The cubic root of 81374617 is about 433.3408715980.

The spelling of 81374617 in words is "eighty-one million, three hundred seventy-four thousand, six hundred seventeen".