18220501 has 8 divisors (see below), whose sum is σ = 19817784. Its totient is φ = 16651200.

The previous prime is 18220493. The next prime is 18220507. The reversal of 18220501 is 10502281.

It can be written as a sum of positive squares in 4 ways, for example, as 998001 + 17222500 = 999^2 + 4150^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18220501 - 2³ = 18220493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18220507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5626 + ... + 8251.

It is an arithmetic number, because the mean of its divisors is an integer number (2477223).

Almost surely, 2^18220501 is an apocalyptic number.

It is an amenable number.

18220501 is a deficient number, since it is larger than the sum of its proper divisors (1597283).

18220501 is a wasteful number, since it uses less digits than its factorization.

18220501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13991.

The product of its (nonzero) digits is 160, while the sum is 19.

The square root of 18220501 is about 4268.5478795487. The cubic root of 18220501 is about 263.1399400796.

Adding to 18220501 its reverse (10502281), we get a palindrome (28722782).

It can be divided in two parts, 18220 and 501, that added together give a triangular number (18721 = T₁₉₃).

The spelling of 18220501 in words is "eighteen million, two hundred twenty thousand, five hundred one".