81352188 has 30 divisors (see below), whose sum is σ = 212671536. Its totient is φ = 27117288.

The previous prime is 81352177. The next prime is 81352189. The reversal of 81352188 is 88125318.

It is a super-3 number, since 3×81352188³ (a number of 25 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81352189) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 125220 + ... + 125867.

Almost surely, 2^81352188 is an apocalyptic number.

It is an amenable number.

81352188 is an abundant number, since it is smaller than the sum of its proper divisors (131319348).

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

81352188 is a wasteful number, since it uses less digits than its factorization.

81352188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251103 (or 251092 counting only the distinct ones).

The product of its digits is 15360, while the sum is 36.

The square root of 81352188 is about 9019.5447778699. The cubic root of 81352188 is about 433.3010545319.

The spelling of 81352188 in words is "eighty-one million, three hundred fifty-two thousand, one hundred eighty-eight".