5166121221 has 8 divisors (see below), whose sum is σ = 7653512960. Its totient is φ = 3444080796.

The previous prime is 5166121199. The next prime is 5166121253. The reversal of 5166121221 is 1221216615.

5166121221 is a `hidden beast` number, since 5 + 16 + 612 + 12 + 21 = 666.

It is not a de Polignac number, because 5166121221 - 2²⁷ = 5031903493 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 191337823 = 5166121221 / (5 + 1 + 6 + 6 + 1 + 2 + 1 + 2 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5166121291) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 95668885 + ... + 95668938.

It is an arithmetic number, because the mean of its divisors is an integer number (956689120).

Almost surely, 2^5166121221 is an apocalyptic number.

It is an amenable number.

5166121221 is a deficient number, since it is larger than the sum of its proper divisors (2487391739).

5166121221 is a wasteful number, since it uses less digits than its factorization.

5166121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191337832 (or 191337826 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 5166121221 is about 71875.7345771158. The cubic root of 5166121221 is about 1728.7075583051.

Adding to 5166121221 its reverse (1221216615), we get a palindrome (6387337836).

The spelling of 5166121221 in words is "five billion, one hundred sixty-six million, one hundred twenty-one thousand, two hundred twenty-one".