6921103223781 has 12 divisors (see below), whose sum is σ = 10007381610252. Its totient is φ = 4609346119296.

The previous prime is 6921103223779. The next prime is 6921103223809. The reversal of 6921103223781 is 1873223011296.

It is a happy number.

6921103223781 is a `hidden beast` number, since 6 + 9 + 211 + 0 + 322 + 37 + 81 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 2641827636900 + 4279275586881 = 1625370^2 + 2068641^2 .

It is not a de Polignac number, because 6921103223781 - 2¹ = 6921103223779 is a prime.

It is a super-2 number, since 2×6921103223781² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6921103223701) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 393548766 + ... + 393566351.

It is an arithmetic number, because the mean of its divisors is an integer number (833948467521).

Almost surely, 2^{6921103223781} is an apocalyptic number.

It is an amenable number.

6921103223781 is a deficient number, since it is larger than the sum of its proper divisors (3086278386471).

6921103223781 is a wasteful number, since it uses less digits than its factorization.

6921103223781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 787116100 (or 787116097 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The spelling of 6921103223781 in words is "six trillion, nine hundred twenty-one billion, one hundred three million, two hundred twenty-three thousand, seven hundred eighty-one".