81189270 has 64 divisors (see below), whose sum is σ = 223992000. Its totient is φ = 20901888.

The previous prime is 81189247. The next prime is 81189301. The reversal of 81189270 is 7298118.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2646 + ... + 13014.

It is an arithmetic number, because the mean of its divisors is an integer number (3499875).

Almost surely, 2^81189270 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81189270, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111996000).

81189270 is an abundant number, since it is smaller than the sum of its proper divisors (142802730).

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

81189270 is a wasteful number, since it uses less digits than its factorization.

81189270 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10414 (or 10408 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 81189270 is about 9010.5088646535. The cubic root of 81189270 is about 433.0116145921.

The spelling of 81189270 in words is "eighty-one million, one hundred eighty-nine thousand, two hundred seventy".