81201188 has 12 divisors (see below), whose sum is σ = 142192512. Its totient is φ = 40574760.

The previous prime is 81201181. The next prime is 81201191. The reversal of 81201188 is 88110218.

It is a super-2 number, since 2×81201188² = 13187265865222688, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81201188.

It is not an unprimeable number, because it can be changed into a prime (81201181) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1781 + ... + 12867.

It is an arithmetic number, because the mean of its divisors is an integer number (11849376).

Almost surely, 2^81201188 is an apocalyptic number.

It is an amenable number.

81201188 is a deficient number, since it is larger than the sum of its proper divisors (60991324).

81201188 is a wasteful number, since it uses less digits than its factorization.

81201188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12922 (or 12920 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 29.

The square root of 81201188 is about 9011.1701792830. The cubic root of 81201188 is about 433.0328012174.

The spelling of 81201188 in words is "eighty-one million, two hundred one thousand, one hundred eighty-eight".