81105290 has 48 divisors (see below), whose sum is σ = 171580032. Its totient is φ = 27520416.

The previous prime is 81105287. The next prime is 81105293. The reversal of 81105290 is 9250118.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81105287) and next prime (81105293).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81105293) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 49667 + ... + 51273.

It is an arithmetic number, because the mean of its divisors is an integer number (3574584).

Almost surely, 2^81105290 is an apocalyptic number.

81105290 is an abundant number, since it is smaller than the sum of its proper divisors (90474742).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81105290 is a wasteful number, since it uses less digits than its factorization.

81105290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1731 (or 1724 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 26.

The square root of 81105290 is about 9005.8475447900. The cubic root of 81105290 is about 432.8622645581.

The spelling of 81105290 in words is "eighty-one million, one hundred five thousand, two hundred ninety".