81144487 has 2 divisors, whose sum is σ = 81144488. Its totient is φ = 81144486.

The previous prime is 81144473. The next prime is 81144493. The reversal of 81144487 is 78444118.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81144487 - 2⁷ = 81144359 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81144467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40572243 + 40572244.

It is an arithmetic number, because the mean of its divisors is an integer number (40572244).

Almost surely, 2^81144487 is an apocalyptic number.

81144487 is a deficient number, since it is larger than the sum of its proper divisors (1).

81144487 is an equidigital number, since it uses as much as digits as its factorization.

81144487 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28672, while the sum is 37.

The square root of 81144487 is about 9008.0234790991. The cubic root of 81144487 is about 432.9319853274.

The spelling of 81144487 in words is "eighty-one million, one hundred forty-four thousand, four hundred eighty-seven".