81100558 has 16 divisors (see below), whose sum is σ = 151668864. Its totient is φ = 31597560.

The previous prime is 81100499. The next prime is 81100561. The reversal of 81100558 is 85500118.

It is a super-3 number, since 3×81100558³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

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, 263160 + ... + 263467.

It is an arithmetic number, because the mean of its divisors is an integer number (9479304).

Almost surely, 2^81100558 is an apocalyptic number.

81100558 is a deficient number, since it is larger than the sum of its proper divisors (70568306).

81100558 is a wasteful number, since it uses less digits than its factorization.

81100558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 526647.

The product of its (nonzero) digits is 1600, while the sum is 28.

The square root of 81100558 is about 9005.5848227641. The cubic root of 81100558 is about 432.8538461016.

The spelling of 81100558 in words is "eighty-one million, one hundred thousand, five hundred fifty-eight".