81376541 has 2 divisors, whose sum is σ = 81376542. Its totient is φ = 81376540.

The previous prime is 81376483. The next prime is 81376543. The reversal of 81376541 is 14567318.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74459641 + 6916900 = 8629^2 + 2630^2 .

It is a cyclic number.

It is not a de Polignac number, because 81376541 - 2²⁶ = 14267677 is a prime.

Together with 81376543, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_4745186 and since 81376541 and 4745186 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81376543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40688270 + 40688271.

It is an arithmetic number, because the mean of its divisors is an integer number (40688271).

Almost surely, 2^81376541 is an apocalyptic number.

It is an amenable number.

81376541 is a deficient number, since it is larger than the sum of its proper divisors (1).

81376541 is an equidigital number, since it uses as much as digits as its factorization.

81376541 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20160, while the sum is 35.

The square root of 81376541 is about 9020.8946895527. The cubic root of 81376541 is about 433.3442868369.

The spelling of 81376541 in words is "eighty-one million, three hundred seventy-six thousand, five hundred forty-one".