7821211253 has 2 divisors, whose sum is σ = 7821211254. Its totient is φ = 7821211252.

The previous prime is 7821211241. The next prime is 7821211259. The reversal of 7821211253 is 3521121287.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7743648004 + 77563249 = 87998^2 + 8807^2 .

It is a cyclic number.

It is not a de Polignac number, because 7821211253 - 2¹⁸ = 7820949109 is a prime.

It is a super-2 number, since 2×7821211253² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7821211259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3910605626 + 3910605627.

It is an arithmetic number, because the mean of its divisors is an integer number (3910605627).

Almost surely, 2^7821211253 is an apocalyptic number.

It is an amenable number.

7821211253 is a deficient number, since it is larger than the sum of its proper divisors (1).

7821211253 is an equidigital number, since it uses as much as digits as its factorization.

7821211253 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6720, while the sum is 32.

The square root of 7821211253 is about 88437.6122077027. The cubic root of 7821211253 is about 1984.9885477960.

The spelling of 7821211253 in words is "seven billion, eight hundred twenty-one million, two hundred eleven thousand, two hundred fifty-three".