1212551553 has 4 divisors (see below), whose sum is σ = 1616735408. Its totient is φ = 808367700.

The previous prime is 1212551551. The next prime is 1212551563. The reversal of 1212551553 is 3551552121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1212551553 - 2¹ = 1212551551 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1212551553.

It is not an unprimeable number, because it can be changed into a prime (1212551551) 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, 202091923 + ... + 202091928.

It is an arithmetic number, because the mean of its divisors is an integer number (404183852).

Almost surely, 2^1212551553 is an apocalyptic number.

It is an amenable number.

1212551553 is a deficient number, since it is larger than the sum of its proper divisors (404183855).

1212551553 is an equidigital number, since it uses as much as digits as its factorization.

1212551553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404183854.

The product of its digits is 7500, while the sum is 30.

The square root of 1212551553 is about 34821.7109430309. The cubic root of 1212551553 is about 1066.3507303360.

The spelling of 1212551553 in words is "one billion, two hundred twelve million, five hundred fifty-one thousand, five hundred fifty-three".