81310555 has 16 divisors (see below), whose sum is σ = 100245600. Its totient is φ = 63289600.

The previous prime is 81310547. The next prime is 81310573. The reversal of 81310555 is 55501318.

It is not a de Polignac number, because 81310555 - 2³ = 81310547 is a prime.

It is a super-2 number, since 2×81310555² = 13222812708816050, 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, 28431 + ... + 31159.

It is an arithmetic number, because the mean of its divisors is an integer number (6265350).

Almost surely, 2^81310555 is an apocalyptic number.

81310555 is a deficient number, since it is larger than the sum of its proper divisors (18935045).

81310555 is a wasteful number, since it uses less digits than its factorization.

81310555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2894.

The product of its (nonzero) digits is 3000, while the sum is 28.

The square root of 81310555 is about 9017.2365500745. The cubic root of 81310555 is about 433.2271261739.

The spelling of 81310555 in words is "eighty-one million, three hundred ten thousand, five hundred fifty-five".