16364921 has 4 divisors (see below), whose sum is σ = 16589172. Its totient is φ = 16140672.

The previous prime is 16364911. The next prime is 16364923. The reversal of 16364921 is 12946361.

16364921 = 2860² + 2861².

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12946361 = 2539 ⋅5099.

It can be written as a sum of positive squares in 2 ways, for example, as 8179600 + 8185321 = 2860^2 + 2861^2 .

It is a cyclic number.

It is not a de Polignac number, because 16364921 - 2¹⁸ = 16102777 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16364923) 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, 112016 + ... + 112161.

It is an arithmetic number, because the mean of its divisors is an integer number (4147293).

Almost surely, 2^16364921 is an apocalyptic number.

16364921 is the 2861-st centered square number.

It is an amenable number.

16364921 is a deficient number, since it is larger than the sum of its proper divisors (224251).

16364921 is an equidigital number, since it uses as much as digits as its factorization.

16364921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224250.

The product of its digits is 7776, while the sum is 32.

The square root of 16364921 is about 4045.3579569675. The cubic root of 16364921 is about 253.8855427023.

The spelling of 16364921 in words is "sixteen million, three hundred sixty-four thousand, nine hundred twenty-one".