1221101210 has 32 divisors (see below), whose sum is σ = 2522437632. Its totient is φ = 416920320.

The previous prime is 1221101209. The next prime is 1221101221. The reversal of 1221101210 is 121011221.

It is a junction number, because it is equal to n+sod(n) for n = 1221101191 and 1221101200.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19322 + ... + 53061.

It is an arithmetic number, because the mean of its divisors is an integer number (78826176).

Almost surely, 2^1221101210 is an apocalyptic number.

1221101210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221101210 is an abundant number, since it is smaller than the sum of its proper divisors (1301336422).

1221101210 is a wasteful number, since it uses less digits than its factorization.

1221101210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72638.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 1221101210 is about 34944.2586128251. The cubic root of 1221101210 is about 1068.8511295387.

Adding to 1221101210 its reverse (121011221), we get a palindrome (1342112431).

The spelling of 1221101210 in words is "one billion, two hundred twenty-one million, one hundred one thousand, two hundred ten".