81313366 has 16 divisors (see below), whose sum is σ = 125148240. Its totient is φ = 39610080.

The previous prime is 81313343. The next prime is 81313367. The reversal of 81313366 is 66331318.

It is a super-2 number, since 2×81313366² = 13223726980499912, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81313367) 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, 9940 + ... + 16168.

It is an arithmetic number, because the mean of its divisors is an integer number (7821765).

Almost surely, 2^81313366 is an apocalyptic number.

81313366 is a deficient number, since it is larger than the sum of its proper divisors (43834874).

81313366 is a wasteful number, since it uses less digits than its factorization.

81313366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6399.

The product of its digits is 7776, while the sum is 31.

The square root of 81313366 is about 9017.3924168797. The cubic root of 81313366 is about 433.2321185041.

The spelling of 81313366 in words is "eighty-one million, three hundred thirteen thousand, three hundred sixty-six".