5121821 has 2 divisors, whose sum is σ = 5121822. Its totient is φ = 5121820.

The previous prime is 5121797. The next prime is 5121833. The reversal of 5121821 is 1281215.

It is a happy number.

5121821 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5040025 + 81796 = 2245^2 + 286^2 .

It is a cyclic number.

It is not a de Polignac number, because 5121821 - 2²² = 927517 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 5121793 and 5121802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5121841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2560910 + 2560911.

It is an arithmetic number, because the mean of its divisors is an integer number (2560911).

Almost surely, 2^5121821 is an apocalyptic number.

It is an amenable number.

5121821 is a deficient number, since it is larger than the sum of its proper divisors (1).

5121821 is an equidigital number, since it uses as much as digits as its factorization.

5121821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 160, while the sum is 20.

The square root of 5121821 is about 2263.1440519772. The cubic root of 5121821 is about 172.3752062471.

Subtracting from 5121821 its reverse (1281215), we obtain a triangular number (3840606 = T₂₇₇₁).

The spelling of 5121821 in words is "five million, one hundred twenty-one thousand, eight hundred twenty-one".