7778138944 has 56 divisors (see below), whose sum is σ = 15609310920. Its totient is φ = 3845259264.

The previous prime is 7778138887. The next prime is 7778138971. The reversal of 7778138944 is 4498318777.

It can be written as a sum of positive squares in 4 ways, for example, as 154753600 + 7623385344 = 12440^2 + 87312^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3680032 + ... + 3682144.

It is an arithmetic number, because the mean of its divisors is an integer number (278737695).

Almost surely, 2^7778138944 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 7778138944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7804655460).

7778138944 is an abundant number, since it is smaller than the sum of its proper divisors (7831171976).

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

7778138944 is a wasteful number, since it uses less digits than its factorization.

7778138944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2747 (or 2737 counting only the distinct ones).

The product of its digits is 9483264, while the sum is 58.

The square root of 7778138944 is about 88193.7579650624. The cubic root of 7778138944 is about 1981.3379848821.

The spelling of 7778138944 in words is "seven billion, seven hundred seventy-eight million, one hundred thirty-eight thousand, nine hundred forty-four".