16667225021 has 4 divisors (see below), whose sum is σ = 16668938844. Its totient is φ = 16665511200.

The previous prime is 16667225009. The next prime is 16667225027. The reversal of 16667225021 is 12052276661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12052276661 = 263 ⋅45826147.

It can be written as a sum of positive squares in 2 ways, for example, as 8569204900 + 8098020121 = 92570^2 + 89989^2 .

It is a cyclic number.

It is not a de Polignac number, because 16667225021 - 2¹⁴ = 16667208637 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 (16667225027) 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, 842240 + ... + 861801.

It is an arithmetic number, because the mean of its divisors is an integer number (4167234711).

Almost surely, 2^16667225021 is an apocalyptic number.

It is an amenable number.

16667225021 is a deficient number, since it is larger than the sum of its proper divisors (1713823).

16667225021 is an equidigital number, since it uses as much as digits as its factorization.

16667225021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1713822.

The product of its (nonzero) digits is 60480, while the sum is 38.

The spelling of 16667225021 in words is "sixteen billion, six hundred sixty-seven million, two hundred twenty-five thousand, twenty-one".