81378527 has 2 divisors, whose sum is σ = 81378528. Its totient is φ = 81378526.

The previous prime is 81378511. The next prime is 81378569. The reversal of 81378527 is 72587318.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81378527 - 2⁴ = 81378511 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81378587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40689263 + 40689264.

It is an arithmetic number, because the mean of its divisors is an integer number (40689264).

Almost surely, 2^81378527 is an apocalyptic number.

81378527 is a deficient number, since it is larger than the sum of its proper divisors (1).

81378527 is an equidigital number, since it uses as much as digits as its factorization.

81378527 is an evil number, because the sum of its binary digits is even.

The product of its digits is 94080, while the sum is 41.

The square root of 81378527 is about 9021.0047666543. The cubic root of 81378527 is about 433.3478120738.

The spelling of 81378527 in words is "eighty-one million, three hundred seventy-eight thousand, five hundred twenty-seven".