81368699 has 2 divisors, whose sum is σ = 81368700. Its totient is φ = 81368698.

The previous prime is 81368669. The next prime is 81368711. The reversal of 81368699 is 99686318.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81368699 is a prime.

It is not a weakly prime, because it can be changed into another prime (81368669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40684349 + 40684350.

It is an arithmetic number, because the mean of its divisors is an integer number (40684350).

Almost surely, 2^81368699 is an apocalyptic number.

81368699 is a deficient number, since it is larger than the sum of its proper divisors (1).

81368699 is an equidigital number, since it uses as much as digits as its factorization.

81368699 is an evil number, because the sum of its binary digits is even.

The product of its digits is 559872, while the sum is 50.

The square root of 81368699 is about 9020.4600215288. The cubic root of 81368699 is about 433.3303663834.

The spelling of 81368699 in words is "eighty-one million, three hundred sixty-eight thousand, six hundred ninety-nine".