6685124021 has 2 divisors, whose sum is σ = 6685124022. Its totient is φ = 6685124020.

The previous prime is 6685124003. The next prime is 6685124023. The reversal of 6685124021 is 1204215866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5713243396 + 971880625 = 75586^2 + 31175^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6685124021 is a prime.

Together with 6685124023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6685124023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3342562010 + 3342562011.

It is an arithmetic number, because the mean of its divisors is an integer number (3342562011).

Almost surely, 2^6685124021 is an apocalyptic number.

It is an amenable number.

6685124021 is a deficient number, since it is larger than the sum of its proper divisors (1).

6685124021 is an equidigital number, since it uses as much as digits as its factorization.

6685124021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23040, while the sum is 35.

The square root of 6685124021 is about 81762.6077189323. The cubic root of 6685124021 is about 1883.8073608333.

Adding to 6685124021 its reverse (1204215866), we get a palindrome (7889339887).

The spelling of 6685124021 in words is "six billion, six hundred eighty-five million, one hundred twenty-four thousand, twenty-one".