18999601 has 4 divisors (see below), whose sum is σ = 19999600. Its totient is φ = 17999604.

The previous prime is 18999583. The next prime is 18999623. The reversal of 18999601 is 10699981.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 10699981 = 739 ⋅14479.

It is a cyclic number.

It is not a de Polignac number, because 18999601 - 2⁷ = 18999473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18999641) 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 3 ways as a sum of consecutive naturals, for example, 499971 + ... + 500008.

It is an arithmetic number, because the mean of its divisors is an integer number (4999900).

Almost surely, 2^18999601 is an apocalyptic number.

It is an amenable number.

18999601 is a deficient number, since it is larger than the sum of its proper divisors (999999).

18999601 is an equidigital number, since it uses as much as digits as its factorization.

18999601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 999998.

The product of its (nonzero) digits is 34992, while the sum is 43.

The square root of 18999601 is about 4358.8531748615. The cubic root of 18999601 is about 266.8382969780.

It can be divided in two parts, 18999 and 601, that added together give a square (19600 = 140²).

The spelling of 18999601 in words is "eighteen million, nine hundred ninety-nine thousand, six hundred one".