81393427 has 2 divisors, whose sum is σ = 81393428. Its totient is φ = 81393426.

The previous prime is 81393419. The next prime is 81393457. The reversal of 81393427 is 72439318.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81393427 - 2³ = 81393419 is a prime.

It is not a weakly prime, because it can be changed into another prime (81393407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40696713 + 40696714.

It is an arithmetic number, because the mean of its divisors is an integer number (40696714).

Almost surely, 2^81393427 is an apocalyptic number.

81393427 is a deficient number, since it is larger than the sum of its proper divisors (1).

81393427 is an equidigital number, since it uses as much as digits as its factorization.

81393427 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 37.

The square root of 81393427 is about 9021.8305792117. The cubic root of 81393427 is about 433.3742583965.

The spelling of 81393427 in words is "eighty-one million, three hundred ninety-three thousand, four hundred twenty-seven".