18220365 has 24 divisors (see below), whose sum is σ = 31770648. Its totient is φ = 9659520.

The previous prime is 18220361. The next prime is 18220387. The reversal of 18220365 is 56302281.

It can be written as a sum of positive squares in 4 ways, for example, as 352836 + 17867529 = 594^2 + 4227^2 .

It is not a de Polignac number, because 18220365 - 2² = 18220361 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18220361) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7027 + ... + 9263.

It is an arithmetic number, because the mean of its divisors is an integer number (1323777).

Almost surely, 2^18220365 is an apocalyptic number.

18220365 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18220365 is a deficient number, since it is larger than the sum of its proper divisors (13550283).

18220365 is a wasteful number, since it uses less digits than its factorization.

18220365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2429 (or 2426 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 18220365 is about 4268.5319490429. The cubic root of 18220365 is about 263.1392853753.

The spelling of 18220365 in words is "eighteen million, two hundred twenty thousand, three hundred sixty-five".