2978640 has 160 divisors (see below), whose sum is σ = 11784960. Its totient is φ = 677376.

The previous prime is 2978629. The next prime is 2978681. The reversal of 2978640 is 468792.

2978640 is a `hidden beast` number, since 2 + 9 + 7 + 8 + 640 = 666.

2978640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 2978595 and 2978604.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15022 + ... + 15218.

It is an arithmetic number, because the mean of its divisors is an integer number (73656).

2^2978640 is an apocalyptic number.

2978640 is a gapful number since it is divisible by the number (20) 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 2978640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5892480).

2978640 is an abundant number, since it is smaller than the sum of its proper divisors (8806320).

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

2978640 is a wasteful number, since it uses less digits than its factorization.

2978640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226 (or 214 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 2978640 is about 1725.8736917863. The cubic root of 2978640 is about 143.8818475265.

The spelling of 2978640 in words is "two million, nine hundred seventy-eight thousand, six hundred forty".