77444640 has 384 divisors, whose sum is σ = 335301120. Its totient is φ = 16257024.

The previous prime is 77444629. The next prime is 77444641. The reversal of 77444640 is 4644477.

77444640 is a `hidden beast` number, since 7 + 7 + 4 + 4 + 4 + 640 = 666.

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 = 77444595 and 77444604.

It is not an unprimeable number, because it can be changed into a prime (77444641) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 393022 + ... + 393218.

It is an arithmetic number, because the mean of its divisors is an integer number (873180).

Almost surely, 2^77444640 is an apocalyptic number.

77444640 is a gapful number since it is divisible by the number (70) 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 77444640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (167650560).

77444640 is an abundant number, since it is smaller than the sum of its proper divisors (257856480).

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

77444640 is a wasteful number, since it uses less digits than its factorization.

77444640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241 (or 227 counting only the distinct ones).

The product of its (nonzero) digits is 75264, while the sum is 36.

The square root of 77444640 is about 8800.2636324147. The cubic root of 77444640 is about 426.2494076123.

The spelling of 77444640 in words is "seventy-seven million, four hundred forty-four thousand, six hundred forty".