12699821 has 2 divisors, whose sum is σ = 12699822. Its totient is φ = 12699820.

The previous prime is 12699811. The next prime is 12699829. The reversal of 12699821 is 12899621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8940100 + 3759721 = 2990^2 + 1939^2 .

It is a cyclic number.

It is not a de Polignac number, because 12699821 - 2²² = 8505517 is a prime.

It is a super-2 number, since 2×12699821² = 322570906864082, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12699829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6349910 + 6349911.

It is an arithmetic number, because the mean of its divisors is an integer number (6349911).

Almost surely, 2^12699821 is an apocalyptic number.

It is an amenable number.

12699821 is a deficient number, since it is larger than the sum of its proper divisors (1).

12699821 is an equidigital number, since it uses as much as digits as its factorization.

12699821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 38.

The square root of 12699821 is about 3563.6808218470. The cubic root of 12699821 is about 233.3095592558.

The spelling of 12699821 in words is "twelve million, six hundred ninety-nine thousand, eight hundred twenty-one".