81306105 has 16 divisors (see below), whose sum is σ = 130812864. Its totient is φ = 43122240.

The previous prime is 81306097. The next prime is 81306119. The reversal of 81306105 is 50160318.

It is not a de Polignac number, because 81306105 - 2³ = 81306097 is a prime.

It is a super-2 number, since 2×81306105² = 13221365420542050, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12259 + ... + 17688.

It is an arithmetic number, because the mean of its divisors is an integer number (8175804).

Almost surely, 2^81306105 is an apocalyptic number.

It is an amenable number.

81306105 is a deficient number, since it is larger than the sum of its proper divisors (49506759).

81306105 is a wasteful number, since it uses less digits than its factorization.

81306105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30136.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 81306105 is about 9016.9897970442. The cubic root of 81306105 is about 433.2192227479.

The spelling of 81306105 in words is "eighty-one million, three hundred six thousand, one hundred five".