81226573 has 4 divisors (see below), whose sum is σ = 81269440. Its totient is φ = 81183708.

The previous prime is 81226571. The next prime is 81226591. The reversal of 81226573 is 37562218.

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, and also an emirpimes, since its reverse is a distinct semiprime: 37562218 = 2 ⋅18781109.

It is a cyclic number.

It is not a de Polignac number, because 81226573 - 2¹ = 81226571 is a prime.

It is a super-2 number, since 2×81226573² = 13195512322648658, 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 (81226571) 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, 18453 + ... + 22426.

It is an arithmetic number, because the mean of its divisors is an integer number (20317360).

Almost surely, 2^81226573 is an apocalyptic number.

It is an amenable number.

81226573 is a deficient number, since it is larger than the sum of its proper divisors (42867).

81226573 is a wasteful number, since it uses less digits than its factorization.

81226573 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42866.

The product of its digits is 20160, while the sum is 34.

The square root of 81226573 is about 9012.5785988251. The cubic root of 81226573 is about 433.0779212156.

The spelling of 81226573 in words is "eighty-one million, two hundred twenty-six thousand, five hundred seventy-three".