1221055953 has 8 divisors (see below), whose sum is σ = 1753311168. Its totient is φ = 751419024.

The previous prime is 1221055943. The next prime is 1221055987. The reversal of 1221055953 is 3595501221.

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

It is not a de Polignac number, because 1221055953 - 2⁵ = 1221055921 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1221055903) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15654525 + ... + 15654602.

It is an arithmetic number, because the mean of its divisors is an integer number (219163896).

Almost surely, 2^1221055953 is an apocalyptic number.

1221055953 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1221055953 is a deficient number, since it is larger than the sum of its proper divisors (532255215).

1221055953 is a wasteful number, since it uses less digits than its factorization.

1221055953 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31309143.

The product of its (nonzero) digits is 13500, while the sum is 33.

The square root of 1221055953 is about 34943.6110469425. The cubic root of 1221055953 is about 1068.8379246292.

The spelling of 1221055953 in words is "one billion, two hundred twenty-one million, fifty-five thousand, nine hundred fifty-three".