8212195921 has 2 divisors, whose sum is σ = 8212195922. Its totient is φ = 8212195920.

The previous prime is 8212195919. The next prime is 8212195951. The reversal of 8212195921 is 1295912128.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4950529600 + 3261666321 = 70360^2 + 57111^2 .

It is a cyclic number.

It is not a de Polignac number, because 8212195921 - 2¹ = 8212195919 is a prime.

Together with 8212195919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (8212195951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4106097960 + 4106097961.

It is an arithmetic number, because the mean of its divisors is an integer number (4106097961).

Almost surely, 2^8212195921 is an apocalyptic number.

It is an amenable number.

8212195921 is a deficient number, since it is larger than the sum of its proper divisors (1).

8212195921 is an equidigital number, since it uses as much as digits as its factorization.

8212195921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 40.

The square root of 8212195921 is about 90621.1670692891. The cubic root of 8212195921 is about 2017.5289131860.

The spelling of 8212195921 in words is "eight billion, two hundred twelve million, one hundred ninety-five thousand, nine hundred twenty-one".