18021465 has 72 divisors (see below), whose sum is σ = 39693888. Its totient is φ = 7479360.

The previous prime is 18021463. The next prime is 18021469. The reversal of 18021465 is 56412081.

18021465 is a `hidden beast` number, since 180 + 21 + 465 = 666.

It is not a de Polignac number, because 18021465 - 2¹ = 18021463 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18021461) 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 71 ways as a sum of consecutive naturals, for example, 23884 + ... + 24626.

It is an arithmetic number, because the mean of its divisors is an integer number (551304).

Almost surely, 2^18021465 is an apocalyptic number.

18021465 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18021465 is an abundant number, since it is smaller than the sum of its proper divisors (21672423).

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

18021465 is a wasteful number, since it uses less digits than its factorization.

18021465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 779 (or 769 counting only the distinct ones).

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

The square root of 18021465 is about 4245.1696079191. The cubic root of 18021465 is about 262.1782725094.

It can be divided in two parts, 1802146 and 5, that added together give a triangular number (1802151 = T₁₈₉₈).

The spelling of 18021465 in words is "eighteen million, twenty-one thousand, four hundred sixty-five".