81045380 has 24 divisors (see below), whose sum is σ = 183287832. Its totient is φ = 29924352.

The previous prime is 81045373. The next prime is 81045383. The reversal of 81045380 is 8354018.

It can be written as a sum of positive squares in 4 ways, for example, as 440896 + 80604484 = 664^2 + 8978^2 .

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (81045383) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 155597 + ... + 156116.

It is an arithmetic number, because the mean of its divisors is an integer number (7636993).

Almost surely, 2^81045380 is an apocalyptic number.

It is an amenable number.

81045380 is an abundant number, since it is smaller than the sum of its proper divisors (102242452).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81045380 is a wasteful number, since it uses less digits than its factorization.

81045380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311735 (or 311733 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 81045380 is about 9002.5207580988. The cubic root of 81045380 is about 432.7556575943.

Adding to 81045380 its reverse (8354018), we get a palindrome (89399398).

The spelling of 81045380 in words is "eighty-one million, forty-five thousand, three hundred eighty".