81168461 has 4 divisors (see below), whose sum is σ = 88547424. Its totient is φ = 73789500.

The previous prime is 81168457. The next prime is 81168487. The reversal of 81168461 is 16486118.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 81168461 - 2² = 81168457 is a prime.

It is a super-2 number, since 2×81168461² = 13176638122217042, 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 (81168401) 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, 3689465 + ... + 3689486.

It is an arithmetic number, because the mean of its divisors is an integer number (22136856).

Almost surely, 2^81168461 is an apocalyptic number.

It is an amenable number.

81168461 is a deficient number, since it is larger than the sum of its proper divisors (7378963).

81168461 is a wasteful number, since it uses less digits than its factorization.

81168461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7378962.

The product of its digits is 9216, while the sum is 35.

The square root of 81168461 is about 9009.3540833958. The cubic root of 81168461 is about 432.9746174675.

The spelling of 81168461 in words is "eighty-one million, one hundred sixty-eight thousand, four hundred sixty-one".