81106616387 has 2 divisors, whose sum is σ = 81106616388. Its totient is φ = 81106616386.

The previous prime is 81106616333. The next prime is 81106616399. The reversal of 81106616387 is 78361660118.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81106616387 - 2¹² = 81106612291 is a prime.

It is not a weakly prime, because it can be changed into another prime (81106606387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40553308193 + 40553308194.

It is an arithmetic number, because the mean of its divisors is an integer number (40553308194).

Almost surely, 2^81106616387 is an apocalyptic number.

81106616387 is a deficient number, since it is larger than the sum of its proper divisors (1).

81106616387 is an equidigital number, since it uses as much as digits as its factorization.

81106616387 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 290304, while the sum is 47.

The spelling of 81106616387 in words is "eighty-one billion, one hundred six million, six hundred sixteen thousand, three hundred eighty-seven".