6821066066840 has 32 divisors (see below), whose sum is σ = 15347647812960. Its totient is φ = 2728382131200.

The previous prime is 6821066066831. The next prime is 6821066066863. The reversal of 6821066066840 is 486606601286.

It is a happy number.

It is a super-2 number, since 2×6821066066840² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1168520 + ... + 3873960.

It is an arithmetic number, because the mean of its divisors is an integer number (479613994155).

Almost surely, 2^{6821066066840} is an apocalyptic number.

It is an amenable number.

6821066066840 is an abundant number, since it is smaller than the sum of its proper divisors (8526581746120).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6821066066840 is a wasteful number, since it uses less digits than its factorization.

6821066066840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2768483 (or 2768479 counting only the distinct ones).

The product of its (nonzero) digits is 3981312, while the sum is 53.

The spelling of 6821066066840 in words is "six trillion, eight hundred twenty-one billion, sixty-six million, sixty-six thousand, eight hundred forty".