12879778640 has 20 divisors (see below), whose sum is σ = 29945485524. Its totient is φ = 5151911424.

The previous prime is 12879778633. The next prime is 12879778657. The reversal of 12879778640 is 4687797821.

It can be written as a sum of positive squares in 2 ways, for example, as 5814367504 + 7065411136 = 76252^2 + 84056^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a self number, because there is not a number n which added to its sum of digits gives 12879778640.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 80498537 + ... + 80498696.

Almost surely, 2^12879778640 is an apocalyptic number.

12879778640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12879778640 is an abundant number, since it is smaller than the sum of its proper divisors (17065706884).

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

12879778640 is a wasteful number, since it uses less digits than its factorization.

12879778640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160997246 (or 160997240 counting only the distinct ones).

The product of its (nonzero) digits is 9483264, while the sum is 59.

The spelling of 12879778640 in words is "twelve billion, eight hundred seventy-nine million, seven hundred seventy-eight thousand, six hundred forty".