81491156167 has 2 divisors, whose sum is σ = 81491156168. Its totient is φ = 81491156166.

The previous prime is 81491156053. The next prime is 81491156177. The reversal of 81491156167 is 76165119418.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81491156167 - 2¹¹ = 81491154119 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81491156167.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81491156177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40745578083 + 40745578084.

It is an arithmetic number, because the mean of its divisors is an integer number (40745578084).

Almost surely, 2^81491156167 is an apocalyptic number.

81491156167 is a deficient number, since it is larger than the sum of its proper divisors (1).

81491156167 is an equidigital number, since it uses as much as digits as its factorization.

81491156167 is an evil number, because the sum of its binary digits is even.

The product of its digits is 362880, while the sum is 49.

The spelling of 81491156167 in words is "eighty-one billion, four hundred ninety-one million, one hundred fifty-six thousand, one hundred sixty-seven".