1221422100 has 72 divisors (see below), whose sum is σ = 3600707040. Its totient is φ = 319562880.

The previous prime is 1221422053. The next prime is 1221422113. The reversal of 1221422100 is 12241221.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1221422100.

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 22510 + ... + 54309.

It is an arithmetic number, because the mean of its divisors is an integer number (50009820).

Almost surely, 2^1221422100 is an apocalyptic number.

1221422100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221422100 is an abundant number, since it is smaller than the sum of its proper divisors (2379284940).

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

1221422100 is a wasteful number, since it uses less digits than its factorization.

1221422100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76889 (or 76882 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 1221422100 is about 34948.8497664802. The cubic root of 1221422100 is about 1068.9447482048.

Adding to 1221422100 its reverse (12241221), we get a palindrome (1233663321).

The spelling of 1221422100 in words is "one billion, two hundred twenty-one million, four hundred twenty-two thousand, one hundred".