1221100010 has 16 divisors (see below), whose sum is σ = 2367055656. Its totient is φ = 450867648.

The previous prime is 1221099967. The next prime is 1221100033. The reversal of 1221100010 is 100011221.

It can be written as a sum of positive squares in 4 ways, for example, as 1022656441 + 198443569 = 31979^2 + 14087^2 .

It is a Curzon 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, 4696409 + ... + 4696668.

Almost surely, 2^1221100010 is an apocalyptic number.

1221100010 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221100010 is a deficient number, since it is larger than the sum of its proper divisors (1145955646).

1221100010 is a wasteful number, since it uses less digits than its factorization.

1221100010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9393097.

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 1221100010 is about 34944.2414426183. The cubic root of 1221100010 is about 1068.8507794117.

Adding to 1221100010 its reverse (100011221), we get a palindrome (1321111231).

The spelling of 1221100010 in words is "one billion, two hundred twenty-one million, one hundred thousand, ten".