81562673 has 4 divisors (see below), whose sum is σ = 82899828. Its totient is φ = 80225520.

The previous prime is 81562667. The next prime is 81562709. The reversal of 81562673 is 37626518.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 976144 + 80586529 = 988^2 + 8977^2 .

It is a cyclic number.

It is not a de Polignac number, because 81562673 - 2¹⁸ = 81300529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81552673) 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, 668486 + ... + 668607.

It is an arithmetic number, because the mean of its divisors is an integer number (20724957).

Almost surely, 2^81562673 is an apocalyptic number.

It is an amenable number.

81562673 is a deficient number, since it is larger than the sum of its proper divisors (1337155).

81562673 is a wasteful number, since it uses less digits than its factorization.

81562673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1337154.

The product of its digits is 60480, while the sum is 38.

The square root of 81562673 is about 9031.2055120012. The cubic root of 81562673 is about 433.6744303841.

The spelling of 81562673 in words is "eighty-one million, five hundred sixty-two thousand, six hundred seventy-three".