6681502921 has 4 divisors (see below), whose sum is σ = 6972003072. Its totient is φ = 6391002772.

The previous prime is 6681502913. The next prime is 6681502991. The reversal of 6681502921 is 1292051866.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6681502921 - 2³ = 6681502913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6681502991) 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, 145250041 + ... + 145250086.

It is an arithmetic number, because the mean of its divisors is an integer number (1743000768).

Almost surely, 2^6681502921 is an apocalyptic number.

It is an amenable number.

6681502921 is a deficient number, since it is larger than the sum of its proper divisors (290500151).

6681502921 is a wasteful number, since it uses less digits than its factorization.

6681502921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290500150.

The product of its (nonzero) digits is 51840, while the sum is 40.

The square root of 6681502921 is about 81740.4607339597. The cubic root of 6681502921 is about 1883.4671683487.

The spelling of 6681502921 in words is "six billion, six hundred eighty-one million, five hundred two thousand, nine hundred twenty-one".