12657821 has 8 divisors (see below), whose sum is σ = 13952064. Its totient is φ = 11387520.

The previous prime is 12657817. The next prime is 12657851. The reversal of 12657821 is 12875621.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12657821 - 2² = 12657817 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12657851) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4865 + ... + 6998.

It is an arithmetic number, because the mean of its divisors is an integer number (1744008).

Almost surely, 2^12657821 is an apocalyptic number.

12657821 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12657821 is a deficient number, since it is larger than the sum of its proper divisors (1294243).

12657821 is a wasteful number, since it uses less digits than its factorization.

12657821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11971.

The product of its digits is 6720, while the sum is 32.

The square root of 12657821 is about 3557.7831580916. The cubic root of 12657821 is about 233.0520799422.

The spelling of 12657821 in words is "twelve million, six hundred fifty-seven thousand, eight hundred twenty-one".