1220402251100 has 144 divisors (see below), whose sum is σ = 2758139467776. Its totient is φ = 468363168000.

The previous prime is 1220402251049. The next prime is 1220402251111. The reversal of 1220402251100 is 11522040221.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 84560885 + ... + 84575315.

It is an arithmetic number, because the mean of its divisors is an integer number (19153746304).

Almost surely, 2^{1220402251100} is an apocalyptic number.

1220402251100 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 1220402251100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1379069733888).

1220402251100 is an abundant number, since it is smaller than the sum of its proper divisors (1537737216676).

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

1220402251100 is a wasteful number, since it uses less digits than its factorization.

1220402251100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14836 (or 14829 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 20.

Adding to 1220402251100 its reverse (11522040221), we get a palindrome (1231924291321).

The spelling of 1220402251100 in words is "one trillion, two hundred twenty billion, four hundred two million, two hundred fifty-one thousand, one hundred".