81272190 has 16 divisors (see below), whose sum is σ = 195053328. Its totient is φ = 21672576.

The previous prime is 81272183. The next prime is 81272207. The reversal of 81272190 is 9127218.

It is a super-3 number, since 3×81272190³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 2709073 = 81272190 / (8 + 1 + 2 + 7 + 2 + 1 + 9 + 0).

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, 1354507 + ... + 1354566.

It is an arithmetic number, because the mean of its divisors is an integer number (12190833).

Almost surely, 2^81272190 is an apocalyptic number.

81272190 is an abundant number, since it is smaller than the sum of its proper divisors (113781138).

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

81272190 is a wasteful number, since it uses less digits than its factorization.

81272190 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2709083.

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 81272190 is about 9015.1089843662. The cubic root of 81272190 is about 433.1589785087.

The spelling of 81272190 in words is "eighty-one million, two hundred seventy-two thousand, one hundred ninety".