1221544210 has 16 divisors (see below), whose sum is σ = 2207544192. Its totient is φ = 486670000.

The previous prime is 1221544169. The next prime is 1221544211. The reversal of 1221544210 is 124451221.

It is not an unprimeable number, because it can be changed into a prime (1221544211) 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 7 ways as a sum of consecutive naturals, for example, 240826 + ... + 245845.

It is an arithmetic number, because the mean of its divisors is an integer number (137971512).

Almost surely, 2^1221544210 is an apocalyptic number.

1221544210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221544210 is a deficient number, since it is larger than the sum of its proper divisors (985999982).

1221544210 is a wasteful number, since it uses less digits than its factorization.

1221544210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 486929.

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 1221544210 is about 34950.5967044913. The cubic root of 1221544210 is about 1068.9803691131.

Adding to 1221544210 its reverse (124451221), we get a palindrome (1345995431).

The spelling of 1221544210 in words is "one billion, two hundred twenty-one million, five hundred forty-four thousand, two hundred ten".