16390121 has 4 divisors (see below), whose sum is σ = 17880144. Its totient is φ = 14900100.

The previous prime is 16390117. The next prime is 16390123. The reversal of 16390121 is 12109361.

It is a happy number.

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: 12109361 = 11 ⋅1100851.

It is a cyclic number.

It is not a de Polignac number, because 16390121 - 2² = 16390117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16390123) 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, 744995 + ... + 745016.

It is an arithmetic number, because the mean of its divisors is an integer number (4470036).

Almost surely, 2^16390121 is an apocalyptic number.

16390121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16390121 is a deficient number, since it is larger than the sum of its proper divisors (1490023).

16390121 is a wasteful number, since it uses less digits than its factorization.

16390121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1490022.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 16390121 is about 4048.4714399388. The cubic root of 16390121 is about 254.0157935495.

Adding to 16390121 its reverse (12109361), we get a palindrome (28499482).

The spelling of 16390121 in words is "sixteen million, three hundred ninety thousand, one hundred twenty-one".