1213204655 has 32 divisors (see below), whose sum is σ = 1644620544. Its totient is φ = 853065216.

The previous prime is 1213204639. The next prime is 1213204679. The reversal of 1213204655 is 5564023121.

It is a cyclic number.

It is not a de Polignac number, because 1213204655 - 2⁴ = 1213204639 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 107669 + ... + 118401.

It is an arithmetic number, because the mean of its divisors is an integer number (51394392).

Almost surely, 2^1213204655 is an apocalyptic number.

1213204655 is a deficient number, since it is larger than the sum of its proper divisors (431415889).

1213204655 is a wasteful number, since it uses less digits than its factorization.

1213204655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10835.

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 1213204655 is about 34831.0874794342. The cubic root of 1213204655 is about 1066.5421478453.

Adding to 1213204655 its reverse (5564023121), we get a palindrome (6777227776).

The spelling of 1213204655 in words is "one billion, two hundred thirteen million, two hundred four thousand, six hundred fifty-five".