81313810 has 16 divisors (see below), whose sum is σ = 146468736. Its totient is φ = 32502448.

The previous prime is 81313723. The next prime is 81313811. The reversal of 81313810 is 1831318.

It is a super-2 number, since 2×81313810² = 13223871393432200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81313811) 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, 22809 + ... + 26131.

It is an arithmetic number, because the mean of its divisors is an integer number (9154296).

Almost surely, 2^81313810 is an apocalyptic number.

81313810 is a deficient number, since it is larger than the sum of its proper divisors (65154926).

81313810 is a wasteful number, since it uses less digits than its factorization.

81313810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5777.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 81313810 is about 9017.4170359366. The cubic root of 81313810 is about 433.2329070367.

The spelling of 81313810 in words is "eighty-one million, three hundred thirteen thousand, eight hundred ten".