6921390244 has 12 divisors (see below), whose sum is σ = 12293215984. Its totient is φ = 3409042824.

The previous prime is 6921390239. The next prime is 6921390247. The reversal of 6921390244 is 4420931296.

It is a junction number, because it is equal to n+sod(n) for n = 6921390197 and 6921390206.

It is not an unprimeable number, because it can be changed into a prime (6921390247) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12912774 + ... + 12913309.

Almost surely, 2^6921390244 is an apocalyptic number.

It is an amenable number.

6921390244 is a deficient number, since it is larger than the sum of its proper divisors (5371825740).

6921390244 is a wasteful number, since it uses less digits than its factorization.

6921390244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25826154 (or 25826152 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 40.

The square root of 6921390244 is about 83194.8931365381. The cubic root of 6921390244 is about 1905.7434925767.

The spelling of 6921390244 in words is "six billion, nine hundred twenty-one million, three hundred ninety thousand, two hundred forty-four".