1221210533 has 4 divisors (see below), whose sum is σ = 1221646560. Its totient is φ = 1220774508.

The previous prime is 1221210517. The next prime is 1221210547. The reversal of 1221210533 is 3350121221.

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 a cyclic number.

It is not a de Polignac number, because 1221210533 - 2⁴ = 1221210517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221210583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 213785 + ... + 219422.

It is an arithmetic number, because the mean of its divisors is an integer number (305411640).

Almost surely, 2^1221210533 is an apocalyptic number.

It is an amenable number.

1221210533 is a deficient number, since it is larger than the sum of its proper divisors (436027).

1221210533 is an equidigital number, since it uses as much as digits as its factorization.

1221210533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 436026.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 1221210533 is about 34945.8228261977. The cubic root of 1221210533 is about 1068.8830260280.

Adding to 1221210533 its reverse (3350121221), we get a palindrome (4571331754).

The spelling of 1221210533 in words is "one billion, two hundred twenty-one million, two hundred ten thousand, five hundred thirty-three".