18220465 has 16 divisors (see below), whose sum is σ = 22640400. Its totient is φ = 14065920.

The previous prime is 18220463. The next prime is 18220469. The reversal of 18220465 is 56402281.

It can be written as a sum of positive squares in 8 ways, for example, as 166464 + 18054001 = 408^2 + 4249^2 .

It is not a de Polignac number, because 18220465 - 2¹ = 18220463 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18220463) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27235 + ... + 27895.

It is an arithmetic number, because the mean of its divisors is an integer number (1415025).

Almost surely, 2^18220465 is an apocalyptic number.

It is an amenable number.

18220465 is a deficient number, since it is larger than the sum of its proper divisors (4419935).

18220465 is a wasteful number, since it uses less digits than its factorization.

18220465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 852.

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 18220465 is about 4268.5436626559. The cubic root of 18220465 is about 263.1397667758.

The spelling of 18220465 in words is "eighteen million, two hundred twenty thousand, four hundred sixty-five".