18216765 has 64 divisors (see below), whose sum is σ = 38085120. Its totient is φ = 8087040.

The previous prime is 18216749. The next prime is 18216767. The reversal of 18216765 is 56761281.

It is not a de Polignac number, because 18216765 - 2⁴ = 18216749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18216767) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 34705 + ... + 35225.

It is an arithmetic number, because the mean of its divisors is an integer number (595080).

Almost surely, 2^18216765 is an apocalyptic number.

18216765 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18216765 is an abundant number, since it is smaller than the sum of its proper divisors (19868355).

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

18216765 is a wasteful number, since it uses less digits than its factorization.

18216765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 579 (or 573 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 18216765 is about 4268.1102375642. The cubic root of 18216765 is about 263.1219537828.

It can be divided in two parts, 18216 and 765, that added together give a palindrome (18981).

The spelling of 18216765 in words is "eighteen million, two hundred sixteen thousand, seven hundred sixty-five".