12347821 has 2 divisors, whose sum is σ = 12347822. Its totient is φ = 12347820.

The previous prime is 12347807. The next prime is 12347843. The reversal of 12347821 is 12874321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10797796 + 1550025 = 3286^2 + 1245^2 .

It is a cyclic number.

It is not a de Polignac number, because 12347821 - 2⁵ = 12347789 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12347821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12347801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6173910 + 6173911.

It is an arithmetic number, because the mean of its divisors is an integer number (6173911).

Almost surely, 2^12347821 is an apocalyptic number.

It is an amenable number.

12347821 is a deficient number, since it is larger than the sum of its proper divisors (1).

12347821 is an equidigital number, since it uses as much as digits as its factorization.

12347821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2688, while the sum is 28.

The square root of 12347821 is about 3513.9466415983. The cubic root of 12347821 is about 231.1337905522.

The spelling of 12347821 in words is "twelve million, three hundred forty-seven thousand, eight hundred twenty-one".