81401461 has 2 divisors, whose sum is σ = 81401462. Its totient is φ = 81401460.

The previous prime is 81401459. The next prime is 81401473. The reversal of 81401461 is 16410418.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66732561 + 14668900 = 8169^2 + 3830^2 .

It is a cyclic number.

It is not a de Polignac number, because 81401461 - 2¹ = 81401459 is a prime.

Together with 81401459, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81401431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40700730 + 40700731.

It is an arithmetic number, because the mean of its divisors is an integer number (40700731).

Almost surely, 2^81401461 is an apocalyptic number.

It is an amenable number.

81401461 is a deficient number, since it is larger than the sum of its proper divisors (1).

81401461 is an equidigital number, since it uses as much as digits as its factorization.

81401461 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 81401461 is about 9022.2758215430. The cubic root of 81401461 is about 433.3885167724.

Adding to 81401461 its reverse (16410418), we get a palindrome (97811879).

The spelling of 81401461 in words is "eighty-one million, four hundred one thousand, four hundred sixty-one".