81923747 has 2 divisors, whose sum is σ = 81923748. Its totient is φ = 81923746.

The previous prime is 81923741. The next prime is 81923749. The reversal of 81923747 is 74732918.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81923747 - 2²⁶ = 14814883 is a prime.

Together with 81923749, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81923741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40961873 + 40961874.

It is an arithmetic number, because the mean of its divisors is an integer number (40961874).

Almost surely, 2^81923747 is an apocalyptic number.

81923747 is a deficient number, since it is larger than the sum of its proper divisors (1).

81923747 is an equidigital number, since it uses as much as digits as its factorization.

81923747 is an evil number, because the sum of its binary digits is even.

The product of its digits is 84672, while the sum is 41.

The square root of 81923747 is about 9051.1737912825. The cubic root of 81923747 is about 434.3134402488.

The spelling of 81923747 in words is "eighty-one million, nine hundred twenty-three thousand, seven hundred forty-seven".