81612941 has 2 divisors, whose sum is σ = 81612942. Its totient is φ = 81612940.

The previous prime is 81612917. The next prime is 81612983. The reversal of 81612941 is 14921618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80102500 + 1510441 = 8950^2 + 1229^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81612941 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 81612898 and 81612907.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81612991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40806470 + 40806471.

It is an arithmetic number, because the mean of its divisors is an integer number (40806471).

Almost surely, 2^81612941 is an apocalyptic number.

It is an amenable number.

81612941 is a deficient number, since it is larger than the sum of its proper divisors (1).

81612941 is an equidigital number, since it uses as much as digits as its factorization.

81612941 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3456, while the sum is 32.

The square root of 81612941 is about 9033.9881005014. The cubic root of 81612941 is about 433.7635049100.

The spelling of 81612941 in words is "eighty-one million, six hundred twelve thousand, nine hundred forty-one".