7977440 has 48 divisors (see below), whose sum is σ = 19132848. Its totient is φ = 3142656.

The previous prime is 7977433. The next prime is 7977443. The reversal of 7977440 is 447797.

It is a junction number, because it is equal to n+sod(n) for n = 7977394 and 7977403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7977443) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 11339 + ... + 12021.

It is an arithmetic number, because the mean of its divisors is an integer number (398601).

Almost surely, 2^7977440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7977440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9566424).

7977440 is an abundant number, since it is smaller than the sum of its proper divisors (11155408).

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

7977440 is a wasteful number, since it uses less digits than its factorization.

7977440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 771 (or 763 counting only the distinct ones).

The product of its (nonzero) digits is 49392, while the sum is 38.

The square root of 7977440 is about 2824.4362269310. The cubic root of 7977440 is about 199.8118230026.

The spelling of 7977440 in words is "seven million, nine hundred seventy-seven thousand, four hundred forty".