1221985055 has 8 divisors (see below), whose sum is σ = 1530137952. Its totient is φ = 935084128.

The previous prime is 1221985031. The next prime is 1221985081. The reversal of 1221985055 is 5505891221.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1221985055 - 2¹² = 1221980959 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5312864 + ... + 5313093.

It is an arithmetic number, because the mean of its divisors is an integer number (191267244).

Almost surely, 2^1221985055 is an apocalyptic number.

1221985055 is a deficient number, since it is larger than the sum of its proper divisors (308152897).

1221985055 is a wasteful number, since it uses less digits than its factorization.

1221985055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10625985.

The product of its (nonzero) digits is 36000, while the sum is 38.

The square root of 1221985055 is about 34956.9028233338. The cubic root of 1221985055 is about 1069.1089489788.

The spelling of 1221985055 in words is "one billion, two hundred twenty-one million, nine hundred eighty-five thousand, fifty-five".