12645821 has 2 divisors, whose sum is σ = 12645822. Its totient is φ = 12645820.

The previous prime is 12645757. The next prime is 12645833. The reversal of 12645821 is 12854621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9369721 + 3276100 = 3061^2 + 1810^2 .

It is a cyclic number.

It is not a de Polignac number, because 12645821 - 2⁶ = 12645757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12605821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6322910 + 6322911.

It is an arithmetic number, because the mean of its divisors is an integer number (6322911).

Almost surely, 2^12645821 is an apocalyptic number.

It is an amenable number.

12645821 is a deficient number, since it is larger than the sum of its proper divisors (1).

12645821 is an equidigital number, since it uses as much as digits as its factorization.

12645821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3840, while the sum is 29.

The square root of 12645821 is about 3556.0963147811. The cubic root of 12645821 is about 232.9784098324.

The spelling of 12645821 in words is "twelve million, six hundred forty-five thousand, eight hundred twenty-one".