2351821 has 2 divisors, whose sum is σ = 2351822. Its totient is φ = 2351820.

The previous prime is 2351803. The next prime is 2351827. The reversal of 2351821 is 1281532.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1929321 + 422500 = 1389^2 + 650^2 .

It is a cyclic number.

It is not a de Polignac number, because 2351821 - 2⁷ = 2351693 is a prime.

2351821 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2351792 and 2351801.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2351827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1175910 + 1175911.

It is an arithmetic number, because the mean of its divisors is an integer number (1175911).

2^2351821 is an apocalyptic number.

It is an amenable number.

2351821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2351821 is an equidigital number, since it uses as much as digits as its factorization.

2351821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 480, while the sum is 22.

The square root of 2351821 is about 1533.5648013697. The cubic root of 2351821 is about 132.9846214340.

The spelling of 2351821 in words is "two million, three hundred fifty-one thousand, eight hundred twenty-one".