6990781 has 12 divisors (see below), whose sum is σ = 8487072. Its totient is φ = 5730648.

The previous prime is 6990761. The next prime is 6990799. The reversal of 6990781 is 1870996.

It is not a de Polignac number, because 6990781 - 2⁵ = 6990749 is a prime.

It is a super-2 number, since 2×6990781² = 97742037979922, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6990701) 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, 1975 + ... + 4228.

It is an arithmetic number, because the mean of its divisors is an integer number (707256).

Almost surely, 2^6990781 is an apocalyptic number.

It is an amenable number.

6990781 is a deficient number, since it is larger than the sum of its proper divisors (1496291).

6990781 is a wasteful number, since it uses less digits than its factorization.

6990781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6240 (or 6233 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 40.

The square root of 6990781 is about 2644.0085098199. The cubic root of 6990781 is about 191.2091037051.

The spelling of 6990781 in words is "six million, nine hundred ninety thousand, seven hundred eighty-one".