16251121 has 4 divisors (see below), whose sum is σ = 16333812. Its totient is φ = 16168432.

The previous prime is 16251113. The next prime is 16251149. The reversal of 16251121 is 12115261.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12115261 = 83 ⋅145967.

It can be written as a sum of positive squares in 2 ways, for example, as 8208225 + 8042896 = 2865^2 + 2836^2 .

It is a cyclic number.

It is not a de Polignac number, because 16251121 - 2³ = 16251113 is a prime.

It is a super-3 number, since 3×16251121³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16255121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41050 + ... + 41443.

It is an arithmetic number, because the mean of its divisors is an integer number (4083453).

Almost surely, 2^16251121 is an apocalyptic number.

It is an amenable number.

16251121 is a deficient number, since it is larger than the sum of its proper divisors (82691).

16251121 is an equidigital number, since it uses as much as digits as its factorization.

16251121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82690.

The product of its digits is 120, while the sum is 19.

The square root of 16251121 is about 4031.2679146889. The cubic root of 16251121 is about 253.2956751888.

Adding to 16251121 its reverse (12115261), we get a palindrome (28366382).

The spelling of 16251121 in words is "sixteen million, two hundred fifty-one thousand, one hundred twenty-one".