81413597 has 4 divisors (see below), whose sum is σ = 81439776. Its totient is φ = 81387420.

The previous prime is 81413593. The next prime is 81413609. The reversal of 81413597 is 79531418.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 79531418 = 2 ⋅39765709.

It is a cyclic number.

It is not a de Polignac number, because 81413597 - 2² = 81413593 is a prime.

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 81413597.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81413593) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7679 + ... + 14892.

It is an arithmetic number, because the mean of its divisors is an integer number (20359944).

Almost surely, 2^81413597 is an apocalyptic number.

It is an amenable number.

81413597 is a deficient number, since it is larger than the sum of its proper divisors (26179).

81413597 is a wasteful number, since it uses less digits than its factorization.

81413597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26178.

The product of its digits is 30240, while the sum is 38.

The square root of 81413597 is about 9022.9483540581. The cubic root of 81413597 is about 433.4100534116.

The spelling of 81413597 in words is "eighty-one million, four hundred thirteen thousand, five hundred ninety-seven".