81036320 has 48 divisors (see below), whose sum is σ = 191999808. Its totient is φ = 32321280.

The previous prime is 81036283. The next prime is 81036359. The reversal of 81036320 is 2363018.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 90917 + ... + 91803.

It is an arithmetic number, because the mean of its divisors is an integer number (3999996).

Almost surely, 2^81036320 is an apocalyptic number.

81036320 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81036320 is an abundant number, since it is smaller than the sum of its proper divisors (110963488).

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

81036320 is a wasteful number, since it uses less digits than its factorization.

81036320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1473 (or 1465 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 81036320 is about 9002.0175516381. The cubic root of 81036320 is about 432.7395311873.

Adding to 81036320 its reverse (2363018), we get a palindrome (83399338).

The spelling of 81036320 in words is "eighty-one million, thirty-six thousand, three hundred twenty".