1220011100 has 72 divisors (see below), whose sum is σ = 3300705408. Its totient is φ = 380260800.

The previous prime is 1220011097. The next prime is 1220011123. The reversal of 1220011100 is 11100221.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 71522 + ... + 86921.

Almost surely, 2^1220011100 is an apocalyptic number.

1220011100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1220011100 is an abundant number, since it is smaller than the sum of its proper divisors (2080694308).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1220011100 is a wasteful number, since it uses less digits than its factorization.

1220011100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158475 (or 158468 counting only the distinct ones).

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

The square root of 1220011100 is about 34928.6572888223. The cubic root of 1220011100 is about 1068.5329707620.

Adding to 1220011100 its reverse (11100221), we get a palindrome (1231111321).

The spelling of 1220011100 in words is "one billion, two hundred twenty million, eleven thousand, one hundred".