6939981 has 6 divisors (see below), whose sum is σ = 10024430. Its totient is φ = 4626648.

The previous prime is 6939967. The next prime is 6940007. The reversal of 6939981 is 1899396.

It can be written as a sum of positive squares in only one way, i.e., 6937956 + 2025 = 2634^2 + 45^2 .

It is not a de Polignac number, because 6939981 - 2¹¹ = 6937933 is a prime.

It is a super-2 number, since 2×6939981² = 96326672560722, which contains 22 as substring.

It is a d-powerful number, because it can be written as 6⁶ + 9² + 3¹⁴ + 9⁴ + 9⁴ + 8⁷ + 1 .

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6939901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 385546 + ... + 385563.

Almost surely, 2^6939981 is an apocalyptic number.

It is an amenable number.

6939981 is a deficient number, since it is larger than the sum of its proper divisors (3084449).

6939981 is a wasteful number, since it uses less digits than its factorization.

6939981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 771115 (or 771112 counting only the distinct ones).

The product of its digits is 104976, while the sum is 45.

The square root of 6939981 is about 2634.3843683107. The cubic root of 6939981 is about 190.7448233844.

The spelling of 6939981 in words is "six million, nine hundred thirty-nine thousand, nine hundred eighty-one".