81768923 has 2 divisors, whose sum is σ = 81768924. Its totient is φ = 81768922.

The previous prime is 81768847. The next prime is 81768931. The reversal of 81768923 is 32986718.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81768923 - 2²² = 77574619 is a prime.

It is not a weakly prime, because it can be changed into another prime (81768943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40884461 + 40884462.

It is an arithmetic number, because the mean of its divisors is an integer number (40884462).

Almost surely, 2^81768923 is an apocalyptic number.

81768923 is a deficient number, since it is larger than the sum of its proper divisors (1).

81768923 is an equidigital number, since it uses as much as digits as its factorization.

81768923 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 44.

The square root of 81768923 is about 9042.6170437545. The cubic root of 81768923 is about 434.0396712446.

The spelling of 81768923 in words is "eighty-one million, seven hundred sixty-eight thousand, nine hundred twenty-three".