81389067 has 16 divisors (see below), whose sum is σ = 112873728. Its totient is φ = 52123680.

The previous prime is 81389023. The next prime is 81389069. The reversal of 81389067 is 76098318.

It is a de Polignac number, because none of the positive numbers 2^k-81389067 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81389069) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2698 + ... + 13040.

It is an arithmetic number, because the mean of its divisors is an integer number (7054608).

Almost surely, 2^81389067 is an apocalyptic number.

81389067 is a deficient number, since it is larger than the sum of its proper divisors (31484661).

81389067 is a wasteful number, since it uses less digits than its factorization.

81389067 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10450.

The product of its (nonzero) digits is 72576, while the sum is 42.

The square root of 81389067 is about 9021.5889398708. The cubic root of 81389067 is about 433.3665200750.

It can be divided in two parts, 8138 and 9067, that added together give a triangular number (17205 = T₁₈₅).

The spelling of 81389067 in words is "eighty-one million, three hundred eighty-nine thousand, sixty-seven".