81242330 has 32 divisors (see below), whose sum is σ = 158230800. Its totient is φ = 29855232.

The previous prime is 81242321. The next prime is 81242339. The reversal of 81242330 is 3324218.

It is an interprime number because it is at equal distance from previous prime (81242321) and next prime (81242339).

It can be written as a sum of positive squares in 8 ways, for example, as 62932489 + 18309841 = 7933^2 + 4279^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81242296 and 81242305.

It is not an unprimeable number, because it can be changed into a prime (81242339) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28406 + ... + 31134.

Almost surely, 2^81242330 is an apocalyptic number.

81242330 is a deficient number, since it is larger than the sum of its proper divisors (76988470).

81242330 is a wasteful number, since it uses less digits than its factorization.

81242330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2978.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 81242330 is about 9013.4527235683. The cubic root of 81242330 is about 433.1059234130.

Adding to 81242330 its reverse (3324218), we get a palindrome (84566548).

The spelling of 81242330 in words is "eighty-one million, two hundred forty-two thousand, three hundred thirty".