18245421 has 6 divisors (see below), whose sum is σ = 26354510. Its totient is φ = 12163608.

The previous prime is 18245419. The next prime is 18245431. The reversal of 18245421 is 12454281.

18245421 is nontrivially palindromic in base 5.

It can be written as a sum of positive squares in only one way, i.e., 16695396 + 1550025 = 4086^2 + 1245^2 .

It is not a de Polignac number, because 18245421 - 2¹ = 18245419 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 (18245411) 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 5 ways as a sum of consecutive naturals, for example, 1013626 + ... + 1013643.

Almost surely, 2^18245421 is an apocalyptic number.

It is an amenable number.

18245421 is a deficient number, since it is larger than the sum of its proper divisors (8109089).

18245421 is a wasteful number, since it uses less digits than its factorization.

18245421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2027275 (or 2027272 counting only the distinct ones).

The product of its digits is 2560, while the sum is 27.

The square root of 18245421 is about 4271.4659076247. The cubic root of 18245421 is about 263.2598500655.

The spelling of 18245421 in words is "eighteen million, two hundred forty-five thousand, four hundred twenty-one".