6859939421 has 2 divisors, whose sum is σ = 6859939422. Its totient is φ = 6859939420.

The previous prime is 6859939409. The next prime is 6859939423. The reversal of 6859939421 is 1249399586.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6595226521 + 264712900 = 81211^2 + 16270^2 .

It is a cyclic number.

It is not a de Polignac number, because 6859939421 - 2¹⁸ = 6859677277 is a prime.

Together with 6859939423, 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 (6859939423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3429969710 + 3429969711.

It is an arithmetic number, because the mean of its divisors is an integer number (3429969711).

Almost surely, 2^6859939421 is an apocalyptic number.

It is an amenable number.

6859939421 is a deficient number, since it is larger than the sum of its proper divisors (1).

6859939421 is an equidigital number, since it uses as much as digits as its factorization.

6859939421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4199040, while the sum is 56.

The square root of 6859939421 is about 82824.7512583044. The cubic root of 6859939421 is about 1900.0867385148.

The spelling of 6859939421 in words is "six billion, eight hundred fifty-nine million, nine hundred thirty-nine thousand, four hundred twenty-one".