81263190 has 32 divisors (see below), whose sum is σ = 205297920. Its totient is φ = 20529504.

The previous prime is 81263173. The next prime is 81263197. The reversal of 81263190 is 9136218.

It is a super-2 number, since 2×81263190² = 13207412097952200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81263197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70714 + ... + 71853.

It is an arithmetic number, because the mean of its divisors is an integer number (6415560).

Almost surely, 2^81263190 is an apocalyptic number.

81263190 is an abundant number, since it is smaller than the sum of its proper divisors (124034730).

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

81263190 is a wasteful number, since it uses less digits than its factorization.

81263190 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142596.

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 81263190 is about 9014.6098085275. The cubic root of 81263190 is about 433.1429887229.

The spelling of 81263190 in words is "eighty-one million, two hundred sixty-three thousand, one hundred ninety".