1221053355 has 12 divisors (see below), whose sum is σ = 2116492560. Its totient is φ = 651228432.

The previous prime is 1221053347. The next prime is 1221053401. The reversal of 1221053355 is 5533501221.

It is a happy number.

1221053355 is a `hidden beast` number, since 122 + 1 + 0 + 533 + 5 + 5 = 666.

It is not a de Polignac number, because 1221053355 - 2³ = 1221053347 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13567215 + ... + 13567304.

It is an arithmetic number, because the mean of its divisors is an integer number (176374380).

Almost surely, 2^1221053355 is an apocalyptic number.

1221053355 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1221053355 is a deficient number, since it is larger than the sum of its proper divisors (895439205).

1221053355 is a wasteful number, since it uses less digits than its factorization.

1221053355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27134530 (or 27134527 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 27.

The square root of 1221053355 is about 34943.5738727452. The cubic root of 1221053355 is about 1068.8371665850.

Adding to 1221053355 its reverse (5533501221), we get a palindrome (6754554576).

The spelling of 1221053355 in words is "one billion, two hundred twenty-one million, fifty-three thousand, three hundred fifty-five".