6787730821 has 4 divisors (see below), whose sum is σ = 6792224544. Its totient is φ = 6783237100.

The previous prime is 6787730819. The next prime is 6787730827. The reversal of 6787730821 is 1280377876.

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 6787730821 - 2¹ = 6787730819 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6787730827) 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, 2244595 + ... + 2247616.

It is an arithmetic number, because the mean of its divisors is an integer number (1698056136).

Almost surely, 2^6787730821 is an apocalyptic number.

It is an amenable number.

6787730821 is a deficient number, since it is larger than the sum of its proper divisors (4493723).

6787730821 is a wasteful number, since it uses less digits than its factorization.

6787730821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4493722.

The product of its (nonzero) digits is 790272, while the sum is 49.

The square root of 6787730821 is about 82387.6861005333. The cubic root of 6787730821 is about 1893.3963566734.

The spelling of 6787730821 in words is "six billion, seven hundred eighty-seven million, seven hundred thirty thousand, eight hundred twenty-one".