1212879555 has 16 divisors (see below), whose sum is σ = 2156230560. Its totient is φ = 646869024.

The previous prime is 1212879527. The next prime is 1212879559. The reversal of 1212879555 is 5559782121.

1212879555 is a `hidden beast` number, since 1 + 2 + 1 + 28 + 79 + 555 = 666.

It is not a de Polignac number, because 1212879555 - 2⁵ = 1212879523 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 1212879555.

It is not an unprimeable number, because it can be changed into a prime (1212879559) 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, 4492012 + ... + 4492281.

It is an arithmetic number, because the mean of its divisors is an integer number (134764410).

Almost surely, 2^1212879555 is an apocalyptic number.

1212879555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1212879555 is a deficient number, since it is larger than the sum of its proper divisors (943351005).

1212879555 is an equidigital number, since it uses as much as digits as its factorization.

1212879555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8984307 (or 8984301 counting only the distinct ones).

The product of its digits is 252000, while the sum is 45.

The square root of 1212879555 is about 34826.4203586875. The cubic root of 1212879555 is about 1066.4468729532.

The spelling of 1212879555 in words is "one billion, two hundred twelve million, eight hundred seventy-nine thousand, five hundred fifty-five".