1217312100 has 81 divisors (see below), whose sum is σ = 3818880793. Its totient is φ = 324337440.

The previous prime is 1217312077. The next prime is 1217312119. The reversal of 1217312100 is 12137121.

It is a happy number.

The square root of 1217312100 is 34890.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 438232356 + 779079744 = 20934^2 + 27912^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1046119 + ... + 1047281.

Almost surely, 2^1217312100 is an apocalyptic number.

1217312100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1217312100 is the 34890-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1217312100

1217312100 is an abundant number, since it is smaller than the sum of its proper divisors (2601568693).

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

1217312100 is a wasteful number, since it uses less digits than its factorization.

1217312100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2346 (or 1173 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 18.

The cubic root of 1217312100 is about 1067.7444260737.

Adding to 1217312100 its reverse (12137121), we get a palindrome (1229449221).

The spelling of 1217312100 in words is "one billion, two hundred seventeen million, three hundred twelve thousand, one hundred".