18203641 has 4 divisors (see below), whose sum is σ = 18249892. Its totient is φ = 18157392.

The previous prime is 18203639. The next prime is 18203657. The reversal of 18203641 is 14630281.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15327225 + 2876416 = 3915^2 + 1696^2 .

It is a cyclic number.

It is not a de Polignac number, because 18203641 - 2¹ = 18203639 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18203611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22530 + ... + 23323.

It is an arithmetic number, because the mean of its divisors is an integer number (4562473).

Almost surely, 2^18203641 is an apocalyptic number.

It is an amenable number.

18203641 is a deficient number, since it is larger than the sum of its proper divisors (46251).

18203641 is an equidigital number, since it uses as much as digits as its factorization.

18203641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46250.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 18203641 is about 4266.5725119820. The cubic root of 18203641 is about 263.0587511573.

It can be divided in two parts, 1820 and 3641, that multiplied together give a triangular number (6626620 = T₃₆₄₀).

The spelling of 18203641 in words is "eighteen million, two hundred three thousand, six hundred forty-one".