6781620 has 24 divisors (see below), whose sum is σ = 18988704. Its totient is φ = 1808416.

The previous prime is 6781609. The next prime is 6781633. The reversal of 6781620 is 261876.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56454 + ... + 56573.

It is an arithmetic number, because the mean of its divisors is an integer number (791196).

Almost surely, 2^6781620 is an apocalyptic number.

6781620 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6781620 is an abundant number, since it is smaller than the sum of its proper divisors (12207084).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6781620 is a wasteful number, since it uses less digits than its factorization.

6781620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113039 (or 113037 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 6781620 is about 2604.1543733043. The cubic root of 6781620 is about 189.2827993923.

The spelling of 6781620 in words is "six million, seven hundred eighty-one thousand, six hundred twenty".