19018121 has 4 divisors (see below), whose sum is σ = 20136852. Its totient is φ = 17899392.

The previous prime is 19018117. The next prime is 19018141. The reversal of 19018121 is 12181091.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12181091 = 13 ⋅937007.

It can be written as a sum of positive squares in 2 ways, for example, as 5593225 + 13424896 = 2365^2 + 3664^2 .

It is a cyclic number.

It is not a de Polignac number, because 19018121 - 2² = 19018117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19018141) 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, 559340 + ... + 559373.

It is an arithmetic number, because the mean of its divisors is an integer number (5034213).

Almost surely, 2^19018121 is an apocalyptic number.

It is an amenable number.

19018121 is a deficient number, since it is larger than the sum of its proper divisors (1118731).

19018121 is a wasteful number, since it uses less digits than its factorization.

19018121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1118730.

The product of its (nonzero) digits is 144, while the sum is 23.

The square root of 19018121 is about 4360.9770694192. The cubic root of 19018121 is about 266.9249696828.

The spelling of 19018121 in words is "nineteen million, eighteen thousand, one hundred twenty-one".