6899909521 has 8 divisors (see below), whose sum is σ = 7020662400. Its totient is φ = 6779283600.

The previous prime is 6899909519. The next prime is 6899909573. The reversal of 6899909521 is 1259099986.

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

It is a cyclic number.

It is not a de Polignac number, because 6899909521 - 2¹ = 6899909519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6899909501) 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, 81400 + ... + 142918.

It is an arithmetic number, because the mean of its divisors is an integer number (877582800).

Almost surely, 2^6899909521 is an apocalyptic number.

It is an amenable number.

6899909521 is a deficient number, since it is larger than the sum of its proper divisors (120752879).

6899909521 is a wasteful number, since it uses less digits than its factorization.

6899909521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63479.

The product of its (nonzero) digits is 3149280, while the sum is 58.

The square root of 6899909521 is about 83065.6940078153. The cubic root of 6899909521 is about 1903.7699405765.

The spelling of 6899909521 in words is "six billion, eight hundred ninety-nine million, nine hundred nine thousand, five hundred twenty-one".