81451330 has 8 divisors (see below), whose sum is σ = 146612412. Its totient is φ = 32580528.

The previous prime is 81451327. The next prime is 81451333. The reversal of 81451330 is 3315418.

It is an interprime number because it is at equal distance from previous prime (81451327) and next prime (81451333).

It can be written as a sum of positive squares in 2 ways, for example, as 78836641 + 2614689 = 8879^2 + 1617^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 81451295 and 81451304.

It is not an unprimeable number, because it can be changed into a prime (81451333) 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, 4072557 + ... + 4072576.

Almost surely, 2^81451330 is an apocalyptic number.

81451330 is a deficient number, since it is larger than the sum of its proper divisors (65161082).

81451330 is a wasteful number, since it uses less digits than its factorization.

81451330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8145140.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 81451330 is about 9025.0390580872. The cubic root of 81451330 is about 433.4770010152.

Adding to 81451330 its reverse (3315418), we get a palindrome (84766748).

The spelling of 81451330 in words is "eighty-one million, four hundred fifty-one thousand, three hundred thirty".