18203428 has 6 divisors (see below), whose sum is σ = 31856006. Its totient is φ = 9101712.

The previous prime is 18203411. The next prime is 18203441. The reversal of 18203428 is 82430281.

It can be written as a sum of positive squares in only one way, i.e., 17239104 + 964324 = 4152^2 + 982^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18203396 and 18203405.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2275425 + ... + 2275432.

Almost surely, 2^18203428 is an apocalyptic number.

It is an amenable number.

18203428 is a deficient number, since it is larger than the sum of its proper divisors (13652578).

18203428 is a wasteful number, since it uses less digits than its factorization.

18203428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4550861 (or 4550859 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 18203428 is about 4266.5475504206. The cubic root of 18203428 is about 263.0577251404.

The spelling of 18203428 in words is "eighteen million, two hundred three thousand, four hundred twenty-eight".