81224774 has 8 divisors (see below), whose sum is σ = 125767488. Its totient is φ = 39302280.

The previous prime is 81224771. The next prime is 81224783. The reversal of 81224774 is 47742218.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×81224774² = 13194927822702152, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81224771) 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, 654977 + ... + 655100.

It is an arithmetic number, because the mean of its divisors is an integer number (15720936).

Almost surely, 2^81224774 is an apocalyptic number.

81224774 is a deficient number, since it is larger than the sum of its proper divisors (44542714).

81224774 is a wasteful number, since it uses less digits than its factorization.

81224774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1310110.

The product of its digits is 25088, while the sum is 35.

The square root of 81224774 is about 9012.4787933176. The cubic root of 81224774 is about 433.0747239330.

The spelling of 81224774 in words is "eighty-one million, two hundred twenty-four thousand, seven hundred seventy-four".