81428528387 has 2 divisors, whose sum is σ = 81428528388. Its totient is φ = 81428528386.

The previous prime is 81428528341. The next prime is 81428528473. The reversal of 81428528387 is 78382582418.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81428528387 - 2¹⁴ = 81428512003 is a prime.

It is not a weakly prime, because it can be changed into another prime (81428528317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40714264193 + 40714264194.

It is an arithmetic number, because the mean of its divisors is an integer number (40714264194).

Almost surely, 2^81428528387 is an apocalyptic number.

81428528387 is a deficient number, since it is larger than the sum of its proper divisors (1).

81428528387 is an equidigital number, since it uses as much as digits as its factorization.

81428528387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6881280, while the sum is 56.

The spelling of 81428528387 in words is "eighty-one billion, four hundred twenty-eight million, five hundred twenty-eight thousand, three hundred eighty-seven".