81382620 has 48 divisors (see below), whose sum is σ = 248588928. Its totient is φ = 19728960.

The previous prime is 81382619. The next prime is 81382627. The reversal of 81382620 is 2628318.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81382627) 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, 60994 + ... + 62313.

It is an arithmetic number, because the mean of its divisors is an integer number (5178936).

Almost surely, 2^81382620 is an apocalyptic number.

It is an amenable number.

81382620 is an abundant number, since it is smaller than the sum of its proper divisors (167206308).

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

81382620 is a wasteful number, since it uses less digits than its factorization.

81382620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123330 (or 123328 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 81382620 is about 9021.2316232319. The cubic root of 81382620 is about 433.3550771469.

The spelling of 81382620 in words is "eighty-one million, three hundred eighty-two thousand, six hundred twenty".