81481797 has 12 divisors (see below), whose sum is σ = 119309164. Its totient is φ = 53576640.

The previous prime is 81481783. The next prime is 81481811. The reversal of 81481797 is 79718418.

81481797 is a `hidden beast` number, since 81 + 481 + 7 + 97 = 666.

It is an interprime number because it is at equal distance from previous prime (81481783) and next prime (81481811).

It can be written as a sum of positive squares in 2 ways, for example, as 64786401 + 16695396 = 8049^2 + 4086^2 .

It is not a de Polignac number, because 81481797 - 2⁷ = 81481669 is a prime.

It is a Duffinian number.

It is a plaindrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81481717) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 61354 + ... + 62667.

Almost surely, 2^81481797 is an apocalyptic number.

It is an amenable number.

81481797 is a deficient number, since it is larger than the sum of its proper divisors (37827367).

81481797 is a wasteful number, since it uses less digits than its factorization.

81481797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124100 (or 124097 counting only the distinct ones).

The product of its digits is 112896, while the sum is 45.

The square root of 81481797 is about 9026.7268154077. The cubic root of 81481797 is about 433.5310418658.

The spelling of 81481797 in words is "eighty-one million, four hundred eighty-one thousand, seven hundred ninety-seven".