6810039821 has 4 divisors (see below), whose sum is σ = 7333889052. Its totient is φ = 6286190592.

The previous prime is 6810039791. The next prime is 6810039823. The reversal of 6810039821 is 1289300186.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 299809225 + 6510230596 = 17315^2 + 80686^2 .

It is a cyclic number.

It is not a de Polignac number, because 6810039821 - 2⁶ = 6810039757 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 (6810039823) 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, 261924596 + ... + 261924621.

It is an arithmetic number, because the mean of its divisors is an integer number (1833472263).

Almost surely, 2^6810039821 is an apocalyptic number.

It is an amenable number.

6810039821 is a deficient number, since it is larger than the sum of its proper divisors (523849231).

6810039821 is a wasteful number, since it uses less digits than its factorization.

6810039821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 523849230.

The product of its (nonzero) digits is 20736, while the sum is 38.

The square root of 6810039821 is about 82522.9654156950. The cubic root of 6810039821 is about 1895.4684083766.

The spelling of 6810039821 in words is "six billion, eight hundred ten million, thirty-nine thousand, eight hundred twenty-one".