6783945121 has 4 divisors (see below), whose sum is σ = 6785752644. Its totient is φ = 6782137600.

The previous prime is 6783945107. The next prime is 6783945127. The reversal of 6783945121 is 1215493876.

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 4047504400 + 2736440721 = 63620^2 + 52311^2 .

It is a cyclic number.

It is not a de Polignac number, because 6783945121 - 2¹¹ = 6783943073 is a prime.

It is a super-2 number, since 2×6783945121² = 92043822809479409282, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6783945127) 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, 898120 + ... + 905641.

It is an arithmetic number, because the mean of its divisors is an integer number (1696438161).

Almost surely, 2^6783945121 is an apocalyptic number.

It is an amenable number.

6783945121 is a deficient number, since it is larger than the sum of its proper divisors (1807523).

6783945121 is a wasteful number, since it uses less digits than its factorization.

6783945121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1807522.

The product of its digits is 362880, while the sum is 46.

The square root of 6783945121 is about 82364.7079822420. The cubic root of 6783945121 is about 1893.0442918595.

The spelling of 6783945121 in words is "six billion, seven hundred eighty-three million, nine hundred forty-five thousand, one hundred twenty-one".