1220120100 has 108 divisors (see below), whose sum is σ = 3990744576. Its totient is φ = 311213760.

The previous prime is 1220120089. The next prime is 1220120113. The reversal of 1220120100 is 10210221.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is an unprimeable number.

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 35 ways as a sum of consecutive naturals, for example, 8772 + ... + 50171.

Almost surely, 2^1220120100 is an apocalyptic number.

1220120100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1220120100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1995372288).

1220120100 is an abundant number, since it is smaller than the sum of its proper divisors (2770624476).

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

1220120100 is a wasteful number, since it uses less digits than its factorization.

1220120100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58986 (or 58976 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 1220120100 is about 34930.2175773355. The cubic root of 1220120100 is about 1068.5647919548.

Adding to 1220120100 its reverse (10210221), we get a palindrome (1230330321).

The spelling of 1220120100 in words is "one billion, two hundred twenty million, one hundred twenty thousand, one hundred".