18312001 has 4 divisors (see below), whose sum is σ = 18331092. Its totient is φ = 18292912.

The previous prime is 18311987. The next prime is 18312013. The reversal of 18312001 is 10021381.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 10021381 = 17 ⋅589493.

It can be written as a sum of positive squares in 2 ways, for example, as 8065600 + 10246401 = 2840^2 + 3201^2 .

It is a cyclic number.

It is not a de Polignac number, because 18312001 - 2¹³ = 18303809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18312101) 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, 8026 + ... + 10051.

It is an arithmetic number, because the mean of its divisors is an integer number (4582773).

Almost surely, 2^18312001 is an apocalyptic number.

It is an amenable number.

18312001 is a deficient number, since it is larger than the sum of its proper divisors (19091).

18312001 is a wasteful number, since it uses less digits than its factorization.

18312001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19090.

The product of its (nonzero) digits is 48, while the sum is 16.

The square root of 18312001 is about 4279.2523879762. The cubic root of 18312001 is about 263.5796848970.

Adding to 18312001 its reverse (10021381), we get a palindrome (28333382).

The spelling of 18312001 in words is "eighteen million, three hundred twelve thousand, one".