81470549 has 4 divisors (see below), whose sum is σ = 82232064. Its totient is φ = 80709036.

The previous prime is 81470533. The next prime is 81470551. The reversal of 81470549 is 94507418.

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 81470549 - 2⁴ = 81470533 is a prime.

It is a super-2 number, since 2×81470549² = 13274900708722802, which contains 22 as substring.

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 (81470569) 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, 380597 + ... + 380810.

It is an arithmetic number, because the mean of its divisors is an integer number (20558016).

Almost surely, 2^81470549 is an apocalyptic number.

It is an amenable number.

81470549 is a deficient number, since it is larger than the sum of its proper divisors (761515).

81470549 is a wasteful number, since it uses less digits than its factorization.

81470549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 761514.

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

The square root of 81470549 is about 9026.1037552202. The cubic root of 81470549 is about 433.5110922912.

The spelling of 81470549 in words is "eighty-one million, four hundred seventy thousand, five hundred forty-nine".