6719921861 has 2 divisors, whose sum is σ = 6719921862. Its totient is φ = 6719921860.

The previous prime is 6719921827. The next prime is 6719921869. The reversal of 6719921861 is 1681299176.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4412944900 + 2306976961 = 66430^2 + 48031^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6719921861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6719921869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3359960930 + 3359960931.

It is an arithmetic number, because the mean of its divisors is an integer number (3359960931).

Almost surely, 2^6719921861 is an apocalyptic number.

It is an amenable number.

6719921861 is a deficient number, since it is larger than the sum of its proper divisors (1).

6719921861 is an equidigital number, since it uses as much as digits as its factorization.

6719921861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 50.

The square root of 6719921861 is about 81975.1295271926. The cubic root of 6719921861 is about 1887.0702778941.

The spelling of 6719921861 in words is "six billion, seven hundred nineteen million, nine hundred twenty-one thousand, eight hundred sixty-one".