78909630644 has 12 divisors (see below), whose sum is σ = 148714304004. Its totient is φ = 36419829504.

The previous prime is 78909630641. The next prime is 78909630647. The reversal of 78909630644 is 44603690987.

It is an interprime number because it is at equal distance from previous prime (78909630641) and next prime (78909630647).

It can be written as a sum of positive squares in 2 ways, for example, as 4849451044 + 74060179600 = 69638^2 + 272140^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 78909630644.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78909630641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 758746397 + ... + 758746500.

It is an arithmetic number, because the mean of its divisors is an integer number (12392858667).

Almost surely, 2^78909630644 is an apocalyptic number.

It is an amenable number.

78909630644 is a deficient number, since it is larger than the sum of its proper divisors (69804673360).

78909630644 is a wasteful number, since it uses less digits than its factorization.

78909630644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1517492914 (or 1517492912 counting only the distinct ones).

The product of its (nonzero) digits is 7838208, while the sum is 56.

The spelling of 78909630644 in words is "seventy-eight billion, nine hundred nine million, six hundred thirty thousand, six hundred forty-four".