81287207 has 2 divisors, whose sum is σ = 81287208. Its totient is φ = 81287206.

The previous prime is 81287201. The next prime is 81287233. The reversal of 81287207 is 70278218.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81287207 - 2⁸ = 81286951 is a prime.

It is a super-2 number, since 2×81287207² = 13215220043721698, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81287201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40643603 + 40643604.

It is an arithmetic number, because the mean of its divisors is an integer number (40643604).

Almost surely, 2^81287207 is an apocalyptic number.

81287207 is a deficient number, since it is larger than the sum of its proper divisors (1).

81287207 is an equidigital number, since it uses as much as digits as its factorization.

81287207 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12544, while the sum is 35.

The square root of 81287207 is about 9015.9418254556. The cubic root of 81287207 is about 433.1856557267.

The spelling of 81287207 in words is "eighty-one million, two hundred eighty-seven thousand, two hundred seven".