6977781 has 6 divisors (see below), whose sum is σ = 10079030. Its totient is φ = 4651848.

The previous prime is 6977767. The next prime is 6977797. The reversal of 6977781 is 1877796.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 4284900 + 2692881 = 2070^2 + 1641^2 .

It is not a de Polignac number, because 6977781 - 2¹⁸ = 6715637 is a prime.

It is a super-2 number, since 2×6977781² = 97378855367922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6977741) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 387646 + ... + 387663.

Almost surely, 2^6977781 is an apocalyptic number.

It is an amenable number.

6977781 is a deficient number, since it is larger than the sum of its proper divisors (3101249).

6977781 is a wasteful number, since it uses less digits than its factorization.

6977781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 775315 (or 775312 counting only the distinct ones).

The product of its digits is 148176, while the sum is 45.

The square root of 6977781 is about 2641.5489773994. The cubic root of 6977781 is about 191.0905065246.

The spelling of 6977781 in words is "six million, nine hundred seventy-seven thousand, seven hundred eighty-one".