181428885 has 48 divisors (see below), whose sum is σ = 344455488. Its totient is φ = 87609600.

The previous prime is 181428881. The next prime is 181428887. The reversal of 181428885 is 588824181.

It is not a de Polignac number, because 181428885 - 2² = 181428881 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 181428885.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181428881) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 154350 + ... + 155520.

It is an arithmetic number, because the mean of its divisors is an integer number (7176156).

Almost surely, 2^181428885 is an apocalyptic number.

181428885 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

181428885 is a deficient number, since it is larger than the sum of its proper divisors (163026603).

181428885 is a wasteful number, since it uses less digits than its factorization.

181428885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1506 (or 1503 counting only the distinct ones).

The product of its digits is 163840, while the sum is 45.

The square root of 181428885 is about 13469.5540015251. The cubic root of 181428885 is about 566.1117171796. Note that the first 3 decimals are identical.

The spelling of 181428885 in words is "one hundred eighty-one million, four hundred twenty-eight thousand, eight hundred eighty-five".