16331261 has 4 divisors (see below), whose sum is σ = 16639452. Its totient is φ = 16023072.

The previous prime is 16331257. The next prime is 16331267. The reversal of 16331261 is 16213361.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16213361 = 2437 ⋅6653.

It can be written as a sum of positive squares in 2 ways, for example, as 3976036 + 12355225 = 1994^2 + 3515^2 .

It is a cyclic number.

It is not a de Polignac number, because 16331261 - 2² = 16331257 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16331267) 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, 154016 + ... + 154121.

It is an arithmetic number, because the mean of its divisors is an integer number (4159863).

Almost surely, 2^16331261 is an apocalyptic number.

It is an amenable number.

16331261 is a deficient number, since it is larger than the sum of its proper divisors (308191).

16331261 is an equidigital number, since it uses as much as digits as its factorization.

16331261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308190.

The product of its digits is 648, while the sum is 23.

The square root of 16331261 is about 4041.1954914357. The cubic root of 16331261 is about 253.7113560345.

The spelling of 16331261 in words is "sixteen million, three hundred thirty-one thousand, two hundred sixty-one".