81412549 has 4 divisors (see below), whose sum is σ = 85697440. Its totient is φ = 77127660.

The previous prime is 81412547. The next prime is 81412553. The reversal of 81412549 is 94521418.

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 81412549 - 2¹ = 81412547 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81412547) 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, 2142417 + ... + 2142454.

It is an arithmetic number, because the mean of its divisors is an integer number (21424360).

Almost surely, 2^81412549 is an apocalyptic number.

It is an amenable number.

81412549 is a deficient number, since it is larger than the sum of its proper divisors (4284891).

81412549 is a wasteful number, since it uses less digits than its factorization.

81412549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4284890.

The product of its digits is 11520, while the sum is 34.

The square root of 81412549 is about 9022.8902797274. The cubic root of 81412549 is about 433.4081937071.

The spelling of 81412549 in words is "eighty-one million, four hundred twelve thousand, five hundred forty-nine".