81013340 has 24 divisors (see below), whose sum is σ = 179082960. Its totient is φ = 30699648.

The previous prime is 81013319. The next prime is 81013351. The reversal of 81013340 is 4331018.

It is a happy number.

It is a super-2 number, since 2×81013340² = 13126322515911200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

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, 106217 + ... + 106976.

It is an arithmetic number, because the mean of its divisors is an integer number (7461790).

Almost surely, 2^81013340 is an apocalyptic number.

It is an amenable number.

81013340 is an abundant number, since it is smaller than the sum of its proper divisors (98069620).

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

81013340 is a wasteful number, since it uses less digits than its factorization.

81013340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213221 (or 213219 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 81013340 is about 9000.7410806000. The cubic root of 81013340 is about 432.6986223924.

Adding to 81013340 its reverse (4331018), we get a palindrome (85344358).

The spelling of 81013340 in words is "eighty-one million, thirteen thousand, three hundred forty".