4194668551921 has 9 divisors (see below), whose sum is σ = 4203356043649. Its totient is φ = 4185998991184.

The previous prime is 4194668551873. The next prime is 4194668551937. The reversal of 4194668551921 is 1291558664914.

The square root of 4194668551921 is 2048089.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 113460511921 + 4081208040000 = 336839^2 + 2020200^2 .

It is not a de Polignac number, because 4194668551921 - 2²⁵ = 4194634997489 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 4194668551921.

It is not an unprimeable number, because it can be changed into a prime (4194668551621) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1140783735 + ... + 1140787411.

Almost surely, 2^{4194668551921} is an apocalyptic number.

4194668551921 is the 2048089-th square number.

4194668551921 is the 1024045-th centered octagonal number.

It is an amenable number.

4194668551921 is a deficient number, since it is larger than the sum of its proper divisors (8687491728).

4194668551921 is an frugal number, since it uses more digits than its factorization.

4194668551921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8468 (or 4234 counting only the distinct ones).

The product of its digits is 18662400, while the sum is 61.

The spelling of 4194668551921 in words is "four trillion, one hundred ninety-four billion, six hundred sixty-eight million, five hundred fifty-one thousand, nine hundred twenty-one".