81961927 has 2 divisors, whose sum is σ = 81961928. Its totient is φ = 81961926.

The previous prime is 81961921. The next prime is 81961961. The reversal of 81961927 is 72916918.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81961927 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81961921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40980963 + 40980964.

It is an arithmetic number, because the mean of its divisors is an integer number (40980964).

Almost surely, 2^81961927 is an apocalyptic number.

81961927 is a deficient number, since it is larger than the sum of its proper divisors (1).

81961927 is an equidigital number, since it uses as much as digits as its factorization.

81961927 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 43.

The square root of 81961927 is about 9053.2826643157. The cubic root of 81961927 is about 434.3808993695.

The spelling of 81961927 in words is "eighty-one million, nine hundred sixty-one thousand, nine hundred twenty-seven".