6461640 has 128 divisors (see below), whose sum is σ = 22348800. Its totient is φ = 1658880.

The previous prime is 6461627. The next prime is 6461657. The reversal of 6461640 is 461646.

6461640 is a `hidden beast` number, since 6 + 4 + 616 + 40 = 666.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 33384 + ... + 33576.

It is an arithmetic number, because the mean of its divisors is an integer number (174600).

Almost surely, 2^6461640 is an apocalyptic number.

6461640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6461640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11174400).

6461640 is an abundant number, since it is smaller than the sum of its proper divisors (15887160).

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

6461640 is a wasteful number, since it uses less digits than its factorization.

6461640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244 (or 234 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 6461640 is about 2541.9756096391. The cubic root of 6461640 is about 186.2577072918.

The spelling of 6461640 in words is "six million, four hundred sixty-one thousand, six hundred forty".