6921906909 has 8 divisors (see below), whose sum is σ = 9280769760. Its totient is φ = 4588824336.

The previous prime is 6921906857. The next prime is 6921906911. The reversal of 6921906909 is 9096091296.

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

It is not a de Polignac number, because 6921906909 - 2¹⁶ = 6921841373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6921906919) 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, 6444442 + ... + 6445515.

It is an arithmetic number, because the mean of its divisors is an integer number (1160096220).

Almost surely, 2^6921906909 is an apocalyptic number.

It is an amenable number.

6921906909 is a deficient number, since it is larger than the sum of its proper divisors (2358862851).

6921906909 is a wasteful number, since it uses less digits than its factorization.

6921906909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12890139.

The product of its (nonzero) digits is 472392, while the sum is 51.

The square root of 6921906909 is about 83197.9982271208. The cubic root of 6921906909 is about 1905.7909111072.

The spelling of 6921906909 in words is "six billion, nine hundred twenty-one million, nine hundred six thousand, nine hundred nine".