81167651 has 2 divisors, whose sum is σ = 81167652. Its totient is φ = 81167650.

The previous prime is 81167633. The next prime is 81167663. The reversal of 81167651 is 15676118.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81167651 - 2²⁶ = 14058787 is a prime.

It is a Chen prime.

It is equal to p_4733774 and since 81167651 and 4733774 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (81164651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40583825 + 40583826.

It is an arithmetic number, because the mean of its divisors is an integer number (40583826).

Almost surely, 2^81167651 is an apocalyptic number.

81167651 is a deficient number, since it is larger than the sum of its proper divisors (1).

81167651 is an equidigital number, since it uses as much as digits as its factorization.

81167651 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10080, while the sum is 35.

The square root of 81167651 is about 9009.3091300055. The cubic root of 81167651 is about 432.9731772094.

It can be divided in two parts, 81167 and 651, that added together give a palindrome (81818).

The spelling of 81167651 in words is "eighty-one million, one hundred sixty-seven thousand, six hundred fifty-one".