81404597 has 4 divisors (see below), whose sum is σ = 81458700. Its totient is φ = 81350496.

The previous prime is 81404593. The next prime is 81404621. The reversal of 81404597 is 79540418.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79540418 = 2 ⋅39770209.

It can be written as a sum of positive squares in 2 ways, for example, as 54302161 + 27102436 = 7369^2 + 5206^2 .

It is a cyclic number.

It is not a de Polignac number, because 81404597 - 2² = 81404593 is a prime.

It is a super-3 number, since 3×81404597³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81404597.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81404591) 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 in 3 ways as a sum of consecutive naturals, for example, 24728 + ... + 27825.

It is an arithmetic number, because the mean of its divisors is an integer number (20364675).

Almost surely, 2^81404597 is an apocalyptic number.

It is an amenable number.

81404597 is a deficient number, since it is larger than the sum of its proper divisors (54103).

81404597 is a wasteful number, since it uses less digits than its factorization.

81404597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54102.

The product of its (nonzero) digits is 40320, while the sum is 38.

The square root of 81404597 is about 9022.4496119402. The cubic root of 81404597 is about 433.3940821473.

The spelling of 81404597 in words is "eighty-one million, four hundred four thousand, five hundred ninety-seven".