12778388555 has 16 divisors (see below), whose sum is σ = 16244432064. Its totient is φ = 9616419840.

The previous prime is 12778388551. The next prime is 12778388621. The reversal of 12778388555 is 55588387721.

It is a happy number.

It is not a de Polignac number, because 12778388555 - 2² = 12778388551 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12778388494 and 12778388503.

It is not an unprimeable number, because it can be changed into a prime (12778388551) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 131690 + ... + 207120.

It is an arithmetic number, because the mean of its divisors is an integer number (1015277004).

Almost surely, 2^12778388555 is an apocalyptic number.

12778388555 is a deficient number, since it is larger than the sum of its proper divisors (3466043509).

12778388555 is a wasteful number, since it uses less digits than its factorization.

12778388555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77446.

The product of its digits is 18816000, while the sum is 59.

The spelling of 12778388555 in words is "twelve billion, seven hundred seventy-eight million, three hundred eighty-eight thousand, five hundred fifty-five".