18201645 has 128 divisors (see below), whose sum is σ = 43130880. Its totient is φ = 7050240.

The previous prime is 18201629. The next prime is 18201649. The reversal of 18201645 is 54610281.

18201645 is a `hidden beast` number, since 18 + 2 + 0 + 1 + 645 = 666.

It is not a de Polignac number, because 18201645 - 2⁴ = 18201629 is a prime.

It is a super-3 number, since 3×18201645³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18201649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 176664 + ... + 176766.

It is an arithmetic number, because the mean of its divisors is an integer number (336960).

Almost surely, 2^18201645 is an apocalyptic number.

18201645 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18201645 is an abundant number, since it is smaller than the sum of its proper divisors (24929235).

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

18201645 is a wasteful number, since it uses less digits than its factorization.

18201645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152 (or 146 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 18201645 is about 4266.3385941578. The cubic root of 18201645 is about 263.0491361494.

The spelling of 18201645 in words is "eighteen million, two hundred one thousand, six hundred forty-five".