6428781 has 8 divisors (see below), whose sum is σ = 9524160. Its totient is φ = 4285836.

The previous prime is 6428777. The next prime is 6428789. The reversal of 6428781 is 1878246.

6428781 is a `hidden beast` number, since 642 + 8 + 7 + 8 + 1 = 666.

It is not a de Polignac number, because 6428781 - 2² = 6428777 is a prime.

It is a super-2 number, since 2×6428781² = 82658450291922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6428789) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119025 + ... + 119078.

It is an arithmetic number, because the mean of its divisors is an integer number (1190520).

Almost surely, 2^6428781 is an apocalyptic number.

It is an amenable number.

6428781 is a deficient number, since it is larger than the sum of its proper divisors (3095379).

6428781 is a wasteful number, since it uses less digits than its factorization.

6428781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238112 (or 238106 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 6428781 is about 2535.5040918918. The cubic root of 6428781 is about 185.9414487922.

The spelling of 6428781 in words is "six million, four hundred twenty-eight thousand, seven hundred eighty-one".