81246320 has 40 divisors (see below), whose sum is σ = 191036880. Its totient is φ = 32130560.

The previous prime is 81246317. The next prime is 81246323. The reversal of 81246320 is 2364218.

It is an interprime number because it is at equal distance from previous prime (81246317) and next prime (81246323).

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 81246320.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81246323) 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, 1415 + ... + 12825.

It is an arithmetic number, because the mean of its divisors is an integer number (4775922).

Almost surely, 2^81246320 is an apocalyptic number.

81246320 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81246320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95518440).

81246320 is an abundant number, since it is smaller than the sum of its proper divisors (109790560).

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

81246320 is a wasteful number, since it uses less digits than its factorization.

81246320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11513 (or 11507 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 81246320 is about 9013.6740566763. The cubic root of 81246320 is about 433.1130135770.

The spelling of 81246320 in words is "eighty-one million, two hundred forty-six thousand, three hundred twenty".