1216100 has 18 divisors (see below), whose sum is σ = 2639154. Its totient is φ = 486400.

The previous prime is 1216091. The next prime is 1216109. The reversal of 1216100 is 16121.

It is an interprime number because it is at equal distance from previous prime (1216091) and next prime (1216109).

It can be written as a sum of positive squares in 3 ways, for example, as 14884 + 1201216 = 122^2 + 1096^2 .

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216109) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5981 + ... + 6180.

2^1216100 is an apocalyptic number.

1216100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1216100 is an abundant number, since it is smaller than the sum of its proper divisors (1423054).

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

1216100 is a wasteful number, since it uses less digits than its factorization.

1216100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12175 (or 12168 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 1216100 is about 1102.7692415007. The cubic root of 1216100 is about 106.7389917477.

The spelling of 1216100 in words is "one million, two hundred sixteen thousand, one hundred".