81788867 has 2 divisors, whose sum is σ = 81788868. Its totient is φ = 81788866.

The previous prime is 81788831. The next prime is 81788923. The reversal of 81788867 is 76888718.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81788867 - 2¹⁶ = 81723331 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81788827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40894433 + 40894434.

It is an arithmetic number, because the mean of its divisors is an integer number (40894434).

Almost surely, 2^81788867 is an apocalyptic number.

81788867 is a deficient number, since it is larger than the sum of its proper divisors (1).

81788867 is an equidigital number, since it uses as much as digits as its factorization.

81788867 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1204224, while the sum is 53.

The square root of 81788867 is about 9043.7197546142. The cubic root of 81788867 is about 434.0749567915.

The spelling of 81788867 in words is "eighty-one million, seven hundred eighty-eight thousand, eight hundred sixty-seven".