6651540 has 72 divisors (see below), whose sum is σ = 23063040. Its totient is φ = 1520064.

The previous prime is 6651523. The next prime is 6651571. The reversal of 6651540 is 451566.

It is a happy number.

6651540 is a `hidden beast` number, since 6 + 651 + 5 + 4 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 1380 + ... + 3899.

It is an arithmetic number, because the mean of its divisors is an integer number (320320).

Almost surely, 2^6651540 is an apocalyptic number.

6651540 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6651540 is an abundant number, since it is smaller than the sum of its proper divisors (16411500).

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

6651540 is a wasteful number, since it uses less digits than its factorization.

6651540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5301 (or 5296 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 6651540 is about 2579.0579675533. The cubic root of 6651540 is about 188.0647505949.

The spelling of 6651540 in words is "six million, six hundred fifty-one thousand, five hundred forty".