81316461 has 8 divisors (see below), whose sum is σ = 108769600. Its totient is φ = 54037152.

The previous prime is 81316453. The next prime is 81316463. The reversal of 81316461 is 16461318.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81316461 - 2³ = 81316453 is a prime.

It is a super-2 number, since 2×81316461² = 13224733659129042, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81316463) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42361 + ... + 44238.

It is an arithmetic number, because the mean of its divisors is an integer number (13596200).

Almost surely, 2^81316461 is an apocalyptic number.

It is an amenable number.

81316461 is a deficient number, since it is larger than the sum of its proper divisors (27453139).

81316461 is a wasteful number, since it uses less digits than its factorization.

81316461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86915.

The product of its digits is 3456, while the sum is 30.

The square root of 81316461 is about 9017.5640280510. The cubic root of 81316461 is about 433.2376150847.

Adding to 81316461 its reverse (16461318), we get a palindrome (97777779).

The spelling of 81316461 in words is "eighty-one million, three hundred sixteen thousand, four hundred sixty-one".